Tag: food

old brown tabby
Behavior

Cognitive Dysfunction Syndrome (CTS) in Elderly Cats

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Meredith Hemphill

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Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

Old brown tabby cat
Photo by Jonas Jaeken on Unsplash

As our cats get older, they can show a variety of signs of aging. Some, like arthritis and a graying muzzle, you probably expect. But did you know that cats (and dogs) can get dementia, just like humans? Cognitive dysfunction in cats is not uncommon in old age [4]. About 30% of cats 11-14 years old and 50% of cats 15+ have changes in behavior unrelated to another health problem [4-6]. This is called Feline Cognitive Decline or Cognitive Dysfunction Syndrome (CDS) in veterinary terms.

What Does Cognitive Dysfunction Syndrome Look Like?

Sordo and Gunn-Moore use the acronym VISHDAAL to help explain the typical indications of cognitive dysfunction in cats. The letters are in order of how common the symptoms are. [5]

  • V is for Vocalization: excessive meowing or yowling, especially at night [1-5]
  • I is for Interactions: changes in the way your cat interacts with members of the household, such as an increased or decreased interest in petting and attention, irritability, aggression toward people/pets, or decreased responsiveness [1, 3, 5, 6]
  • S is for Sleep-wake cycle: changes in the cat’s sleep-wake cycle, particularly being awake during hours of the night when they used to sleep [1-6]
  • H is for House-soiling: that is, urinating and/or defecating outside the litterbox [1-6]
  • D is for Disorientation: being confused about place or time, e.g. getting lost in familiar locations, becoming somehow stuck in places they should be able to get out of easily, not remembering that they’ve just been fed, staring blankly into space [1-6]
  • A is for Activity levels: either decreased activity, e.g. less grooming, lack of interest in food or play, or increased activity in the form of restlessness [1-6]
  • A is for Anxiety: this can manifest in a variety of ways depending upon the individual cat and may contribute to other symptoms [1-6]
  • L is for Learning and memory: forgetting routines, commands, and familiar people, pets, or places [2-6]

Not every cat will exhibit every symptom, and CTS is a condition that changes and progresses over time [5, 6]. Some of the first signs of CTS may be subtle, and many cat parents mistake them for a normal part of aging that they can’t do anything about [1, 5, 6]. However, if you notice any of these symptoms in your senior cat, you absolutely should tell your veterinarian [1, 3]. The vet can confirm a diagnosis and come up with a treatment plan to make your cat’s last years as peaceful as possible.

Cara’s Story

Cara was one of my childhood cats. She was born under our front porch when I was five or six years old, along with two sisters and a brother. We kept her and her brother, Milo, and they were with us into my college years. Cara was always sort of an odd duck. She wanted attention only rarely, stuck her head in shoes, and stared down into the floor vents for extended periods of time. But when she got to be maybe eight or nine years old, she started getting weirder.

The garage was the cats’ home base, and when they wanted out there they would stand at the door and meow. But Cara started going up to any closed door in the house and meowing to go out. She started actually rubbing against us and demanding attention. She started peeing in the bathtub. Cara had kidney problems, as many old cats do, but we never could figure out why it was just the bathtub. She became much more vocal, as well, although if she was meowing in the middle of night, we never heard it since they slept in the garage. No one in my family knew that pets could get dementia until we saw it with Cara.

Diagnosing Cognitive Dysfunction Syndrome

CDS is a diagnosis of exclusion because many of the symptoms can also be caused by medical problems that are common in senior cats [1-3, 5, 6]. For example, pain from arthritis might cause irritability or decreased activity [1, 2, 5]. Vision or hearing loss might cause a cat to become disoriented [1, 2]. It’s important to rule out other medical causes through testing [5]. Only then can your veterinarian be sure that CDS is the culprit.

What Causes Cognitive Dysfunction in Cats?

No one knows for sure what causes CDS. Just like Alzheimer’s disease in humans, it is still somewhat of a mystery. Veterinarians have a few ideas, however. As cats get older, their brains accumulate certain kinds of age-related damage [4-6]. Their brains eventually shrink and lose neural connections, just like ours do [5]. Toxic beta-amyloid plaques and abnormal tau proteins build up in the brain over time [4-6]. Impaired blood flow and oxidative damage are also age-related changes that contribute to cognitive dysfunction in cats [4-6]. The brain is expected to deteriorate with age, just like the rest of the body [3]. However, handling dementia in your elderly pet isn’t as straightforward as some of the other conditions common in senior cats because it isn’t one-size-fits all.

How is Feline Cognitive Dysfunction Treated?

Tan cat laying on sidewalk
Image by Anna Armbrust from Pixabay

There is no cure for CDS, but there are things you can do to make things easier for your cat if they are diagnosed with it [3, 5, 6]. A lot of it has to do with adjusting your cat’s environment to make things easier for them [1, 3]. Keeping to a strict routine makes everything easier to remember and less stressful [1, 5]. Avoid major changes, such as introducing a new pet, if at all possible [2, 3]. If your cat is up all night, you can make a point to keep them active during the day and play with them in the evening hours [1]. Cats that are soiling outside the litterbox may be forgetting where the litter box is or how they’re supposed to use it [1]. Add more litterboxes in easy-to-see places [1-3].

Anxiety may be helped by giving your cat more attention, playing the radio at night/when you’re not home, or using a calming pheromone diffuser like Feliway [1, 3, 5]. Every cat is different, though, so expect some trial-and-error. Ask your veterinarian for recommendations based upon your cats specific symptoms [1, 5]. It may help to consult a cat behaviorist, too [1].

A special diet can sometimes help with CDS [2, 3, 5, 6]. Vitamin E and antioxidants are believed to aid an aging cat’s brain [2, 3, 5]. There are cat foods available that are high in these nutrients [5]. Ask your veterinarian or local pet store for a recommendation. You can also buy supplements, but be careful, because they are usually formulated for dogs and may not be safe for cats [5]. Only use a supplement that is clearly labeled as safe for cats!

Medication

There aren’t any medications specifically for cognitive dysfunction in cats yet; nonetheless, there are some that your veterinarian may prescribe. Anti-anxiety medication is one option [1-3, 5]. The drug selegiline/Anipryl is approved for CDS in dogs and is sometimes prescribed for cats [1, 2, 5, 6]. Not all cats with CDS require medication, however, and their needs can change over time. Take your senior kitty into the vet for regular appointments to reassess what their needs are [6].

Sources

  1. American Society for the Prevention of Cruelty to Animals. (n.d.). Older cats with behavior problems. ASPCA. https://www.aspca.org/pet-care/cat-care/common-cat-behavior-issues/older-cats-behavior-problems
  2. Cornell Feline Health Center. (2018, July). Cognitive dysfunction. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/cognitive-dysfunction
  3. International Cat Care. (2018, August 17). Senility, dementia or cognitive dysfunction syndrome. https://icatcare.org/advice/senility-dementia-or-cognitive-dysfunction-syndrome/
  4. Kornreich, B. (2022, September 27). Feline cognitive dysfunction syndrome (CTS). Cornell Feline Health Center Monthly Health Tips. [Email Newsletter]
  5. Sordo, L. and Gunn-Moore, D. A. (2021). Cognitive dysfunction in cats: Update on neuropathological and behavioural changes plus clinical management. VetRecord, 188(1), e3. https://doi.org/10.1002/vetr.3
  6. Stilwell, N. (2019). Unpacking feline dementia: A veterinary guide. Vetted, 115(5), 6-8. https://www.dvm360.com/view/unpacking-feline-dementia-veterinary-guide

Published October 1st, 2023

Cat Care

Which human foods are toxic to cats?

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Meredith Hemphill

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Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

Cat with cup of coffee and tin of nuts
Image by Mimzy from Pixabay

If you live in the United States, then Thanksgiving is coming up soon. If you live somewhere else, the winter holiday season is coming everywhere. Holidays often mean special food and family meals. While our pets may be family, that doesn’t mean they can eat all the same things we can. It’s never a good idea to feed pets from the table, but things happen. Scraps fall to the floor. Kids may not know any better. Some pets, my cat included, are incorrigible food thieves and will steal from any plate left unattended for a single second. Sometimes, it’s not a big deal. But there are certain human foods that are toxic to cats. Here are the ones to be extra careful about.

Fruits and Veggies

Alliums

Root vegetables in the genus Allium include onions, garlic, shallots, leeks, scallions, and chives. All are toxic to cats. They usually don’t pose a danger unless consumed in large amounts, but it’s always best to be safe. Alliums contain several chemicals, primarily n-propyl disulphide, which cause the hemoglobin in cats’ red blood cells to break down (1, 2). Affected cats become anemic, which can be very dangerous. There is no antidote, but there are effective treatments, so be sure to seek veterinary care for any suspected ingestion or worrying symptoms right away (1).

Toxicity is possible no matter what form the vegetable is in–cooked, raw, powdered, dehydrated, garlic bread, etc. Be particularly careful of adding broth to your cat’s food, which can be a good way to keep them hydrated as long as the broth doesn’t have any alliums in it (3).

Early symptoms of allium toxicity are usually gastrointestinal: nausea, vomiting, diarrhea, loss of appetite, and abdominal pain. If anemia sets in, a day or two after ingestion cats will experience pale gums, lethargy, weakness, jaundice, rapid heartrate, rapid/labored breathing, and dark urine ranging from orange to brown in color (1, 4). These symptoms mean an immediate vet visit is in order.

Grapes

It is well-established that dogs can develop fatal kidney failure from eating even small amounts of grapes, raisins, currants, or sultanas. No one is quite sure why. It also remains unclear whether cats are also susceptible. The current advice is to keep grapes away from cats just in case. They are extremely toxic in dogs, and no one wants to find out the hard way that cats are, too. The toxic dose in dogs is highly variable (1), so if you realize your cat has eaten any amount of grapes or grape products, i.e. raisins, go ahead and take them to the vet right away.

Avocado

Avocadoes are actually poisonous to quite a few animals, including birds, rabbits, and horses in addition to cats and dogs (1, 5). The leaves, bark, seed, and fruit of avocadoes contain a natural fungicide called persin (1, 2). While some animals are very sensitive to persin, cats usually experience only gastrointestinal upset (2). However, not much is known about the particulars of avocado toxicity yet, such as the lethal dose, so it’s best to use a lot of caution (1). In other words, watch that bowl of guacamole carefully, or better yet, don’t put it out where the cat can get into it.

When avocado toxicity does lead to serious or even fatal symptoms–most commonly in birds–it does so by causing fluid accumulation in the chest (1). Respiratory and cardiac symptoms should be taken seriously under any circumstances. If your cat did get into the guac, though, be on the lookout for them. They could indicate unusually serious poisoning.

Brown kitten with apple
Not the seeds, please! – Image by Raissa Meres Rah Meres from Pixabay

Citrus

Citrus plants contain citric acid and essential oils in their stems, leaves, fruits, rinds, and seeds. These chemicals are toxic to cats (5, 6). Small amounts will only upset their stomachs, but a large ingestion can cause serious gastrointestinal distress and even central nervous system depression (5, 6). The fruit contains lower levels of the compounds than other parts of the plant, including the rind.

Coconut

The fresh meat and milk of coconuts contains oils that the feline digestive system doesn’t care for (5). Coconuts can give cats upset stomachs and diarrhea (5, 6). Small amounts may not give them any trouble, however, and it isn’t deadly by any means. Coconut water, on the other hand, can actually be dangerous. It contains high levels of potassium that are not safe for cats (5, 6).

Solanum

The genus Solanum, although part of the nightshade family, contains a lot of agriculturally important vegetables, including tomatoes and potatoes. But even these hold a dark secret. Green tomatoes and green, raw potatoes are poisonous to our cats (1, 2, 7). They contain a chemical called glycoalkaloid solanine which causes severe gastrointestinal symptoms when ingested (2).

Fortunately, glycoalkaloid solanine tastes bitter, as poisonous chemicals in nature usually do (2). Some cats won’t be deterred by this, however. We know this because cats have been poisoned by green tomatoes and potatoes (1). And I once had to pry my cat’s jaws open to get a pill out of her mouth that she was determined to chew up and consume. Those are pretty bitter, too, but that was not stopping her. Best to keep the ripening produce away from the cats, and be careful of any scraps. Especially if you’re making the time-honored Southern dish of fried green tomatoes.

Seeds and Pits

Speaking of scraps, there are several kinds of seeds and pits that can be poisonous even though the fruit itself is not. Apple seeds, apricot pits, cherry pits, and peach pits should all be carefully discarded where cats cannot get to them (7). On that note, it is important that any compost bins and trash cans where food is disposed of are cat-proof.

Beverages

Caffeine

All caffeinated beverages are toxic to cats. Caffeine itself is the culprit. Caffeine belongs to a class of chemicals called methylxanthines, which are toxic to pets (1, 4-6). Cats cannot handle nearly as much caffeine as humans can. A sip may not cause any problems, but too much caffeine can be very harmful or even fatal. Symptoms of caffeine poisoning in cats include hyperactivity, rapid heartrate, tremors, labored breathing, and seizures (3).

Alcohol

Cat looking out window at ice cream cone
Photo by Dids from Pexels

Alcohol is a part of the festivities for many people, but your cat should never participate. Cats are very sensitive to alcohol, and even tiny amounts can give them alcohol poisoning. If you suspect your cat has ingested any alcohol at all, treat it as an emergency. Alcohol poisoning can absolutely be fatal. The symptoms include lethargy, vomiting, diarrhea, labored breathing, lack of coordination, disorientation, tremors, and coma (1, 3-6).

To prevent poisoning, it’s important to prevent access. Open drinks should not be left sitting around. Of course, at a bustling family gathering or holiday party, this is easier said than done. If you don’t trust your guests to keep their glasses in hand or out of your cat’s reach, you may need to put the cat(s) up in a safe room for the duration of the event. Make sure to clean up any spills either way. Cats like to drink from puddles.

Milk

Milk and other dairy products are not toxic to cats, per se, but they can still make them sick. Adult cats are lactose intolerant and usually don’t handle dairy well. I already wrote an article about cats and milk. If you want to know more, you are welcome to read it. I see no need to reinvent the wheel.

Snacks and Scraps

Chocolate

Chocolate also contains methylxanthines: caffeine, which we already discussed, and theobromine (1, 6, 8). Theobromine is found naturally in cacao beans at a concentration of 1-2% (1). Different kinds of chocolate have varying amounts of theobromine. As a rule, the darker or less sweetened the chocolate, the more theobromine. Pets metabolize theobromine much slower than humans, so it doesn’t take much chocolate to lead to toxicity (1).

Symptoms of poisoning typically present in 6 to 12 hours of ingestion (1). They include vomiting, diarrhea, abdominal pain, increased thirst, increased urination, rapid or abnormal heartrate, labored breathing, tremors, seizures, and a drop in blood pressure (1, 3-6). Heart attacks, heart failure, coma, and death can result in severe cases (1, 3). If you think your cat has eaten chocolate, of any kind, take them to the vet. Be sure to tell the vet what kind of chocolate you think they ate and how much, as well as how recently (8). That provides a ballpark for the quantity of methylxanthines consumed (8).

Salt

All animals need some amount of sodium to be healthy, but it’s always possible to get too much of a good thing. If your cat eats too many salty human snacks, or licks up a bunch of straight-up salt for whatever reason, they’ll have adverse effects. I even heard of this happening with a cat licking someone’s salt lamp, although that might be an urban legend. What’s certain is that cats are not designed to eat a whole bag of potato chips. If they manage to steal away with one or two, don’t panic. But don’t make a habit of feeding them salty things.

Dessert cups sitting on wood table
Photo by RODNAE Productions from Pexels

As a cat starts to get a little too much salt in the system, they start to exhibit increased thirst and urination (5). Their body is trying to flush out the excess salt. If it succeeds, that may be the end of it. More serious salt poisoning, however, can lead to vomiting, diarrhea, tremors, high body temperature, seizures, and maybe even death (5, 6).

Nuts

Salted nuts present a particular problem vis-à-vis the above, but even plain nuts can be of concern. They aren’t poisonous, exactly, but they contain lots of oils and fats that can cause vomiting and diarrhea (5, 6). The feline digestive system isn’t really equipped to digest nuggets of plant fats like that. Pets are also sometimes allergic to peanuts just like humans are, so peanuts and peanut products pose an additional risk (1).

Yeast Dough

Although baked bread is safe enough for cats, if not especially nutritious, raw dough containing yeast is very, very dangerous. There are two problems, both of which could be deadly on their own. Fermenting yeast produces carbon dioxide, which causes it to rise, and alcohol. When eaten, the alcohol can cause alcohol poisoning, as described earlier. But the expanding dough can cause a host of problems as well. It can cause the stomach to bloat, or worse yet to twist, which can be life-threatening (5, 6). It can also block the digestive tract and may even require surgery to remove (3). A small amount of raw dough can quickly become a very serious health risk. Take your cat to the vet immediately if you suspect they have consumed any at all.

Xylitol

Xylitol is an artificial sweetener. It is common in lots of products, including gum, candy, baked goods, and toothpaste. It is non-toxic to humans but very toxic to dogs, and it remains unknown whether it is toxic to cats (2). Currently, it is advised to err on the side of caution and assume it may be toxic to cats.

In dogs and some other species, xylitol tricks the body into releasing insulin even though no real sugar is present in the blood stream (1, 5). The large, unnecessary insulin release causes a severe drop in blood sugar and may lead to liver failure and death (1, 2, 5). The symptoms in dogs include vomiting, lethargy, weakness, loss of coordination, and seizures (1, 5, 6). To be on the safe side, check to make sure anything you plan to feed your cat does not contain xylitol, and take them to the vet if they happen to eat anything that does.

Bones

I suspect you already know that bones are not toxic. And cats are carnivores, so wouldn’t bones be part of their natural diet? Yes, cats do crunch up little tiny prey bones in the wild. But feral cats do not hunt turkeys.

The problem with giving your cat bones to gnaw on is that the bones in the kind of animals humans eat are often too big for cats to consume. So they may choke, break their teeth, or splinter off pieces of bone that then stab into their mouths or throats or–well, nowhere is good, is it? Never just throw your cat a bone. Or your dog, for that matter, because they can have the same problems. So no, bones aren’t toxic, but I included them because they can be dangerous and it would be an easy mistake to make.

Works Cited

  1. Kovalkovičová, N., Šutiaková, I., Pistl, J., and Šutiak, V. (2009). Some food toxic for pets. Interdisciplinary Toxicology, 2(3), 169-176. doi: 10.2478/v10102-009-0012-4
  2. Syufy, F. (2020, June 22). Human foods that are toxic cats. The Spruce Pets. https://www.thesprucepets.com/human-food-and-cats-551947
  3. Nicholas, J. (2017, November 20). 14 human foods you shouldn’t give to your cat. Preventive Vet. https://www.preventivevet.com/cats/human-foods-you-should-not-give-to-your-cat
  4. Hill’s Pet. (2019, October 30). Foods that are dangerous or toxic to cats. Hill’s Pet Nutrition, Inc. https://www.hillspet.com/cat-care/nutrition-feeding/toxic-foods-for-cats
  5. ASPCA Poison Control Center. (n.d.). People foods to avoid feeding your pets. https://www.aspca.org/pet-care/animal-poison-control/people-foods-avoid-feeding-your-pets
  6. Dowdy, S.M. (2020, August 24). 15 toxic human foods you should never feed your cat. Daily Paws. https://www.dailypaws.com/cats-kittens/nutrition/what-can-cats-eat/foods-toxic-to-cats
  7. Purina. (n.d.). Harmful substances and poisonous foods for cats. https://www.purina.co.uk/cats/health-and-nutrition/what-not-to-feed/harmful-foods-and-substances
  8. Falls Village Veterinary Hospital. (n.d.). 4 household foods toxic to dogs and cats. https://raleighncvet.com/illness-disease/4-foods-toxic-to-dogs-cats/
Cat Care

In Search of the Best Cat Food, Part V: Do Indoor Cats Need Indoor Food?

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Meredith Hemphill

mehshadoweye

Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

At last, we have come to the final installment of our series on cat food. There remain many questions, I admit, but I am only one person, and there are so, so many kinds of cat food. So I have tried to cover the basics to the best of my ability, and I hope you have learned as much as I have. Today we bring this journey to a close with a question that has haunted me for a long time. Is indoor cat food better for indoor cats?

Image by Crepessuzette from Pixabay

I had always assumed it must be. Why would they make food just for indoor cats (and dogs) if they’re nutritional needs weren’t somehow different? When I became a proper adult and had to buy food for my own kitten, I realized it was actually kind of difficult to find indoor kitten food, and I started to wonder if it might just be a marketing gimmick. But a couple years prior, when I’d bought my hedgehog, I was told I should feed her either hedgehog food or indoor cat food, and indoor cat food only. I was receiving conflicting signals, and I never really got a clear answer. Now the confusion shall end.

The simple answer to the question of whether indoor cats need indoor food is: it depends on the cat. Isn’t that so often the case? The lives of indoor and outdoor cats differ in many ways, but individual cats can be at least as different from each other in either environment, so you have to get to know your cat and possibly ask your veterinarian whether an indoor diet is appropriate, and I’ll explain why momentarily. First, let’s look at what exactly an indoor cat food is.

The formulations vary by company, as is to be expected, but the one thing all indoor diets have in common is a lower calorie content than other cat food. Indoor cats simply do not have the space to roam that outdoor or semi-outdoor cats do, so indoor cats are generally less active and may become overweight. Most indoor diets are also high in fiber. This contributes to the lower calorie count and helps prevent hairballs (1). Indoor cats spend more time grooming than outdoor cats. They may also shed more, being in an environment of consistent light and temperature that confuses their normal shedding cycles (1). Therefore, more hairballs.

Cats tend to be a lot more acrobatic outdoors – Image by rihaij from Pixabay

Some indoor diets may also claim to improve stool quality and/or smell (1, 2). Hill’s Science Diet lists immune-supporting antioxidants and high levels of the fat-burning amino acid carnitine as features of their indoor diet, in addition to low calories and high fiber (3). It is generally agreed that the basic nutritional requirements of indoor and outdoor cats are no different (1, 4). That being said, some indoor cats certainly do have problems with gaining too much weight or coughing up too many hairballs. These cats may benefit from an indoor diet. Changes in weight and lots of hairballs can both be indicative of medical problems, so be sure to check with your veterinarian that there isn’t something more serious going on.

There are some drawbacks to an indoor diet, of course. In in order to decrease calories and increase fiber, the protein content may have to be sacrificed (4). Make sure to carefully examine the protein content so that you know if your cat will be getting enough. Because of the way pet food labels are written, you may have to do some math. See part one of this series for a cat’s protein requirements. Some cats may also benefit more from a diet that is low calorie only or hairball-preventative only. As in, why restrict calories any more than you have to if your cat just needs help with their hairballs? Moreover, many “light” or “low-calorie” cat foods are essentially the same as an indoor diet (1), so keep that in mind when trying to decide what the best option for an overweight kitty is.

To bring things full circle, some indoor cats are likely to benefit from an indoor diet. My first cats, Milo and Cara, absolutely did. Both were very lazy kitties, and it was a struggle to keep their weight under control for much of their lives. Milo was a shorthair, but he shed like crazy, and Cara had long, luscious hair. Both had hairballs, especially Cara. They were fed indoor food most of their lives to help those problems. While Milo was still a pretty fat cat, it did seem to make a difference. I fed Joon an indoor diet for a while because I thought I had to, but I have since stopped. There is nothing inactive about that cat, and her short, fine hair has never given her a hairball in her life. Each cat is different.

Indoor cats can be couch potatoes – Image by photosforyou from Pixabay

I suppose that’s really what this series comes down to. Each cat is different, and each owner has to make the best decisions they can for their cat or cats. There are some things that are true for all cats. They are obligate carnivores. There are certain key nutrients that have to be included in their diets which omnivorous animals like us don’t need. They need to get enough water from their food to be sufficiently hydrated. But every kitty is an individual, and their needs change throughout their life, too. Just like us. The approach to pet food has been pretty one-size-fits-all for a long time. The baffling variety of options today hopefully reflects a shift toward a more flexible, individual approach. It’s our responsibility as pet parents to make sure we look past the marketing to find the best cat food we can for our furry friends.

Post Script: In case anyone was wondering, I still don’t know why hedgehogs must have indoor cat food. If you would like to enlighten me, I am all ears.

Works Cited

  1. Loria, K. (2018, January 22). What’s the difference between indoor cat food and regular cat food? Pet Central, Chewy. https://petcentral.chewy.com/whats-the-difference-between-indoor-cat-food-and-regular-cat-food/
  2. Purina. (n.d.). Feeding your indoor cat. https://www.purina.co.uk/cats/health-and-nutrition/daily-feeding-guide/feeding-your-indoor-cat
  3. Hill’s Pet. (2019, October 30). Nutritional needs of an indoor cat. https://www.hillspet.com/cat-care/nutrition-feeding/best-cat-food-for-indoor-cats-nutritional-needs
  4. Nielsen, M. (2020, May 15). Indoor cat food vs regular food: Why and what to choose. Feline Living. https://www.felineliving.net/indoor-cat-food-vs-regular/#
  5. Country Veterinary Clinic. (n.d.). Best food for indoor cats. Country Veterinary Clinic Blog. https://www.countryvet.net/post/best-food-for-indoor-cats.html

Published August 23rd, 2020

Updated October 15th, 2020

Cat Care

In Search of the Best Cat Food, Part IV: Grain-Free, L.I.D., & Raw Diets

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Meredith Hemphill

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Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

There are trends in pet food just like there are among humans. Increasingly, there has been a movement toward more “natural” pet foods. The idea is to feed pets a diet in line with what they would eat in the wild or what their ancestors ate. However, as my mother is fond of saying, arsenic is natural, too. We need to look past the marketing and make sure that these diets are really all they’re cracked up to be.

Grain-Free Diets

Photo by Nick Fewings on Unsplash

Grain-free diets are fairly self-explanatory. They contain no grains, i.e. wheat, corn, oats, rice, or any other crop in the group. These foods are also gluten-free, but not all gluten-free cat foods are grain-free, as gluten is a protein found in wheat, so other grains may still be included in some gluten-free diets. The concept behind grain-free cat food is that cats, as obligate carnivores, would not include grains in their native diet, which is mostly true. Cats would not chow down on grains in the wild, but they do eat their prey in its entirety, including the stomach contents, which can certainly include grains or other vegetation. The argument that a high-carbohydrate diet is unhealthy for cats still stands nonetheless, and this has largely been the appeal of grain-free cat food.

A Tufts University Study compared 35 grain-free dry cat diets to 42 regular dry cat diets and found that the average carbohydrate content of the grain-free diets was 12 g/1000 kcal lower (1). The individual carbohydrate contents varied widely, however, so it depends a lot upon the food in question (5). The carbohydrate levels are not all that matters, however. Cats are known to be able to digest grains and obtain nutrition from them (2, 3). Considering that cats evolved eating lots of rodents and rodents eat lots of grains, this makes sense.

Grain-free foods don’t simply ditch the carbohydrates–they replace the grains with starchy vegetables like potatoes, lentils, cassava, or peas. There isn’t much research on how digestible these plants are or how bioavailable their nutrients (3). At least some cats get gastrointestinal symptoms from consuming them (4, 5).

Some owners may choose grain-free diets over concerns about food allergies. But food allergies are uncommon in cats. A 2018 study found that only 0.1% of cats had them (10). When food allergies do develop, it is usually to animal products like beef or dairy, not plants (2, 3, 4). Gluten intolerance has not been documented in cats, so that’s no reason to avoid grains (3). Obviously, if your cat really does have a documented allergy to a grain, then you want to make sure their diet is at least free of that grain. If you suspect an allergy, talk to your veterinarian before you do anything else.

I would be remiss if I didn’t mention the concerns about grain-free diets and heart problems that have been brought up in the last several years. Although the connections are primarily being investigated in dogs, it has been impossible not to wonder if there is reason to be worried about cats. Around 2017-18, veterinarians began to raise concerns over cases they saw of dogs fed grain-free diets developing dilated cardiomyopathy, a form of heart disease causing an enlarged heart (6).

The US Food and Drug Administration (FDA) decided to investigate, and they still are. It’s thought that taurine deficiency might play a part, and diets containing legumes or potatoes as the primary carbohydrate might be the culprits, but it remains unclear (7). There were only a handful of reports on cats, so the FDA chose to focus on dogs, and there has been no further word on whether there may be a link between a grain-free diet and heart problems in cats (6).

Grain-free diets, at least the way they are manufactured today, are probably not as beneficial as we may have been led to believe. They may even be harmful, although more research will have to be done for us to know for sure. I’ll admit, I used to be one of those people who thought I had to feed my cats grain-free food. It sounds so much healthier for them! But that’s what marketing is for, isn’t it?

Limited Ingredient Diets

Limited ingredient diets, or L.I.D., are not just one thing. L.I.D. is a bit of an umbrella term, encompassing a group of diets that have a narrower range of ingredients than usual. They are generally meant for cats with known or suspected food allergies, and in fact they can be helpful for such cats. L.I.D. often contain only single protein and carbohydrate sources, i.e. lamb and rice or salmon and potato (8, 9). This makes is easy to be sure that a cat with food allergies or sensitivities is not eating an ingredient they are allergic to.

Novel source of protein? – Image by sven kopping from Pixabay

Many L.I.D. are made with “novel” sources of protein and/or carbohydrates that pets are unlikely to have encountered before, and therefore probably won’t have developed an allergy to (8, 9). These range from the rather mundane–duck, rabbit, sweet potato–to the very out in left field–alligator, kangaroo (8, 9). L.I.D. may also be used as part of a series of elimination diets to figure out what a cat with suspected food allergies is allergic to, under veterinary supervision (9).

Aside from cats with food allergies, some L.I.D.s may be helpful for cats with sensitive digestion as well (8). Otherwise, there is really no particular need for a healthy cat to be on a L.I.D. If you think your cat might benefit from one, especially if you suspect your cat may be suffering from allergies, talk to your veterinarian about it. Most cats with allergies are allergic to fleas or something else in their environment, not their food (10). If food allergies are suspected, there is a long process of testing via elimination diets to determine what, if anything, in the diet your cat is allergic to (9).

Raw Diets

This is a tough nut to crack. While I was doing my research, I read a particular article which was harshly critical of raw diets for cats. One of the drawbacks they listed was that there has been very little research done on these diets. As someone who was lately a research scientist, I kind of want to bash my head against a wall. The solution to a lack of research is to do the research, not to declare that the under-researched thing is bad.

But the fact that there is currently a lot of anecdotal information and not much in the way of scientific studies is a lot of the problem with raw diets, I think. It’s difficult to decide whether the proponents or the detractors have the firmer position because both have only a handful of studies to back them up. The rest is a matter of logic, tangential information, and beliefs.

Before we go any further down this rabbit hole, let’s talk about what a raw diet is. The definition can be a bit variable, but the basic principle is that the food is made of uncooked ingredients. A raw pet diet is mostly muscle meat, organs, ground bone, eggs, and sometimes vegetables, fruits, and dairy (11). Some people make homemade raw diets, but they can be purchased in a variety of forms as well. The goal is to simulate the natural diet of the pet, or its ancestors in the case of dogs, which are highly domesticated animals and don’t really have a natural diet. For cats, their diet in the wild, ideally, is whole prey animals like mice, birds, fish, and small reptiles.

Image by A_Different_Perspective from Pixabay

Proponents of raw diets for cats say that raw meat is more nutritionally sound, having not been exposed to heat that might break down or alter nutrients, and it’s more biologically appropriate for cats anyway (12, 13). They claim that the diet can prevent or alleviate many feline ailments (13, 14). The evidence for this remains anecdotal, but this will necessarily be the case until rigorous research is done to investigate. Nonetheless, some veterinarians have begun to recommend raw diets based on their experience with them, but most fall into the other camp.

The detractors of raw diets, and there are many, say that raw diets are dangerous and have no major benefits. The American Veterinary Medical Association, American Animal Hospital Association, Companion Animal Parasite Council, and Centers for Disease Control have all taken a position against feeding pets raw diets (15). The primary concern is food-borne infections. This is the reason public health authorities tell us humans not to eat undercooked meat and to carefully avoid cross-contamination. Raw food, especially raw animal products, can carry bacteria and parasites. And studies have shown that raw pet foods do (12, 15), which is to be expected, really. The professionals who decry raw pet foods take the position that the risk of disease to both pets and humans outweighs what little benefit, if any, they see in these diets.

Even here there are two sides: those in favor point out that cats, being carnivores, have short, acidic digestive tracts designed for digesting meaty meals without allowing pathogens to proliferate in their guts (13, 14). Not to mention that cooked pet foods have been found to be contaminated with pathogens or toxins before, so perhaps to say raw foods are unsafe draws a false comparison (13)? That’s another case where I doubt anyone has crunched enough data to be sure. Even raw diet cheerleaders readily say that owners need to be careful not to give themselves food poisoning if they feed their cats a raw diet. Using proper food-handling technique should prevent any problems. It’s also important to dispose of uneaten food promptly and cleaning and sanitizing the food dish, as well as the area around it if any food gets on the floor.

Is raw food a good idea for your cat? In general, there’s so little concrete information that it’s hard to say. My instinct is that cats are carnivores, so it should be fine, as long as the diet is well-balanced. It needs to be either an approved commercial diet (AAFCO-approved in the United States) or a homemade diet using a recipe designed by a veterinarian or veterinary nutritionist. If you are thinking about going the homemade route, be very careful about looking for recipes on the internet, because there are lots of them, and many are just made up by people with cats, not experts in cat nutrition.

Also, some cats and some households should not use raw diets. Cats on immunosuppressants (like chemotherapy drugs) or high doses of steroids should not be feed raw food diets, as their immune systems may be more vulnerable to the pathogens in raw animal products (13). Households with very young children or elderly people, or anyone with a compromised immune system, probably shouldn’t use a raw cat food, either (11, 12, 13). Pathogens from their food can pass into a cat’s stool and even remain on the cat, especially on their face, in addition to the aforementioned concerns of pathogens being on food prep and feeding surfaces (12). In a home where there are people–or pets–with weak immune systems, this could be very dangerous. The jury may be out on raw diets in general, but there is definitely a subset of households where they will never be appropriate.

Works Cited

  1. Prantil, L.R., Heinze, C.R., and Freeman, L.M. (2017). Comparison of carbohydrate content between grain-containing and grain-free dry cat diets and between reported and calculated carbohydrate values. Journal of Feline Medicine and Surgery, 20(4), 349-355. https://journals.sagepub.com/doi/full/10.1177/1098612X17710842
  2. Freeman, L.M., Linder, D.E., and Heinze, C.R. (2016, June 14). Grain-free diets: Big on marketing, small on truth. Petfoodology. https://vetnutrition.tufts.edu/2016/06/grain-free-diets-big-on-marketing-small-on-truth/
  3. Cats Only Vet Hospital. (2019, June 3). Grain free and other marketing trends. https://catsonlyvethosp.com/grain-free-other-marketing-trends/
  4. Buzhardt, L. (n.d.) What’s in my cat’s food?: Designer diets, grain free diets. VCA Hospitals. https://vcahospitals.com/know-your-pet/whats-in-my-cats-food-designer-diets-grain-free-diets
  5. Heinze, C.R. (2017, July 3). Research update: New insight into grain-free cat diets. Petfoodology. https://vetnutrition.tufts.edu/2017/07/research-update-new-insight-into-grain-free-cat-diets/
  6. Cats Herd You. (2018, August 22). What do grain-free pet food warnings mean for cats? https://catsherdyou.com/what-do-grain-free-pet-food-warnings-mean-for-cats/
  7. US Food and Drug Administration. (2018, July 12). FDA investigating potential connection between diet and cases of canine heart disease. https://www.fda.gov/animal-veterinary/cvm-updates/fda-investigating-potential-connection-between-diet-and-cases-canine-heart-disease
  8. LID diets for dogs and cats. (2017, June 26). Pet Central, Chewy. https://petcentral.chewy.com/lid-diets-dogs-cats/
  9. Anderson, K. (2020, July 2). Meals that heal: The best food for cats with allergies. The Dog People, Rover. https://www.rover.com/blog/best-food-cats-with-allergies/
  10. Burns, K. (2018, June 27). Banfield: Few pets allergic to food; flea, environmental allergies rise. American Veterinary Medical Association. https://www.avma.org/javma-news/2018-07-15/banfield-few-pets-allergic-food-flea-environmental-allergies-rise
  11. Association of American Feed Council Officials. (2012). Raw foods. https://talkspetfood.aafco.org/rawfoods
  12. Stregowski, J. (2020, April 30). Should you feed your cat a raw diet? The Spruce Pets. https://www.thesprucepets.com/raw-food-diet-for-cats-552329
  13. Tasi, A. (2020, January 6). Feeding raw: A veterinarian’s view. The Conscious Cat with Ingrid King. https://consciouscat.net/2020/01/06/feeding-raw-a-veterinarians-view/
  14. Pierson, L.A. (2016, November). Feeding your cat: Knowing the basics of feline nutrition. Cat Info. https://catinfo.org/#Home-Prepared_Diets
  15. Paul, M. (2014, September 24). The dangers of a raw diet for your cat. Pet Health Network. http://www.pethealthnetwork.com/cat-health/cat-diet-nutrition/dangers-a-raw-diet-your-cat

Published August 9th, 2020

Updated October 29th, 2020

Cat Care

In Search of the Best Cat Food, Part III: Kitten, Adult, & Senior Diets

mehshadoweye

Meredith Hemphill

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Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

The pet food industry offers diets for every stage of a cat’s life, from formula for newborn kittens to senior cat food. The kitten milk-replacement is one thing, but what’s the difference between solid food for kittens, adults, and seniors? And what about the cat food that says it’s for “all life stages”? Today we look at the difference between diets for the various life stages and what really matters for your cat.

Cat and two kittens eating from bowls
Image by mariahuusgaard from Pixabay

Kitten Food

Before doing this research, I knew there was at least one difference between kitten food and any other cat food. I took Joon in when she was about four months old, and I was living with a roommate that already had a cat. Domino is a gorgeous tuxedo cat with spooky yellow eyes, and she was quite pudgy. My roommate had to put her on a diet, and Domino was not a fan. She kept eating Joon’s food, which Joon was too busy playing to care about. My vet told me I should be careful to keep her from doing this, because kitten food is high in calories.

It makes sense, doesn’t it? Kittens are still growing rapidly, and as they get older they use up a lot of energy playing as well. In fact, kittens may need up to three times as many calories as an adult cat each day (1, 2, 3)! And they have higher protein requirements than adults, as well, needing to get about 30% of all that energy from protein (2). Most of the rest of the calories need to come from fat to ensure that they get enough essential fatty acids for proper development (1). Kittens need lots of vitamins and minerals as well. Basically, like all babies, kittens need lots of nutrients in their diet so they can grow up big and strong. So kitten food is made more nutrient-dense than adult food.

The Association of American Feed Control Officials (AAFCO) requires kitten food to be at least 30% protein and 9% fat on a dry matter basis (4). A survey of 212 adult and kitten foods by IdleCat found that kitten foods actually averaged 40.77% protein for kibble and 49.11% protein for canned food (3). The fat content was a little closer to the minimum recommendation, but for both kinds of food was more than 21% higher than the average fat content of the adult foods (3). Carbohydrate and fiber content were lower to compensate (3). Vitamins and minerals weren’t measured in that survey, but in a well-balanced kitten food they should be present in higher amounts as well.

Kitten food is also made to be easier for small mouths with developing teeth to eat. Canned kitten diets are typically softer, and the kibble comes in smaller pieces (1). However, the nutritional differences are what is most likely to impact a cat’s health. Adult cat food is usually not nutrient-dense enough for kittens, although it will do temporarily in a pinch (5). Conversely, as my vet told me, kitten food can cause adult cats to gain too much weight. Depending on the nutrients included, the extra vitamins and minerals could even cause toxicity in an adult cat (1). A few bites here or there is unlikely to cause anybody any harm–Domino is certainly none the worse for it–but kittens need kitten food and adults should be kept away from it as best we can.

Cats are considered kittens up to one year of age, with the exception of some large breeds. Maine Coons do not reach maturity for up to two years. If you are unsure how long to keep feeding your cat a kitten diet, check with your veterinarian.

Tortoiseshell cat eating from bowl
Image by sweetlouise from Pixabay

Adult Cat Food

Adult cat foods are formulated to maintain a grown cat’s weight and health. Growth and development never completely stop. All organisms continue to make new cells, repair damaged tissues, and progress through their life cycle as long as they live. However, an adult cat uses much less energy than a kitten to do these things, so they need far fewer calories and other nutrients relative to their body weight. This is reflected in the nutritive content of adult cat food.

The AAFCO divides their standards for cat food into two categories: “growth and reproduction,” for kittens and pregnant or lactating queens, and “adult maintenance” for the average, older, and sterilized adult cat (6). The minimum protein content for adult maintenance is 4% lower than the recommendation for kittens and queens. The fat minimum is the same, but 5 out of 12 mineral recommendations are lower for adults, as well as Vitamin A (4). These minerals and vitamin can cause toxicity in excess, which is more likely in adult cats who use less of the nutrients than a growing kitten or a queen who is growing kittens.

Cats are typically considered “adults” from the age of one year to seven years, although this varies some by breed and individual cat (7). Those of us with rescue cats often don’t know exactly how old they are, so you and your vet may have to play it by ear to decide when the time seems right to start treating your cat like a senior.

Senior Cat Food

In the United States, the AAFCO is the government body responsible for licensing pet food, and as previously indicated, they don’t issue standards for senior cat food. The consequence of this is that senior cat food is very similar to adult cat food, with some slight modifications that won’t color outside the AAFCO adult cat food guidelines (8). Whether this is a bad thing or not is hard to say. A lot remains unknown about the needs of senior cats. Due to lack of research, many of the decisions made about how to feed senior pets have been made based on what is known about aging humans (9). Even so, there have been improvements in senior cat diets over the years.

But some cats may not need to go on a senior diet at all, or not until much later in life. If an older cat is keeping up their body weight and muscle condition on their adult diet, there’s no need to change them to a senior diet (8). If a senior kitty begins to gain or lose weight or lose muscle mass and no associated health problem is found, a change in diet may be in order (8). However, senior cat diets can be pretty different from one another. Of course, cats with age-related health problems may be put on a diet specific to their needs. If your vet recommends just plain senior cat food, however, the variability in formulations can be overwhelming.

Fat tortoiseshell cat
Cats sometimes gain weight as they get older – Image by Quinn Kampschroer from Pixabay

It used to be the case that senior cat food was low protein, low fat, and high fiber (8), and the myth that senior cats need a diet low in protein still persists. Some health conditions may call for a low-protein diet, but a normal senior cat may suffer greater muscle loss with less protein (9).

Whether or not senior cats need more protein than adult cats is still unclear, however, and may depend upon the individual cat. If they are notably losing muscle mass, then a high-protein senior diet may be the solution (10). There are still senior diets made with low amounts of protein, all the way to those with enhanced protein, so it pays to check the label. Remember that it’s the dry weight of the nutrients that you need to compare, as the amounts on pet food labels are given in minimum and maximum percentages instead of absolute quantities. Check out this page for a rundown of how that math works.

Senior formulas may be low-calorie, hence the traditional wisdom of making them high-fiber, and for some cats this is appropriate. Generally, cats tend to have progressively slower metabolisms up to eleven years of age and are prone to obesity during middle age, around years six to eight (11). Once they get older than that, they often start to lose weight and may need high calorie diets (11).

Sometimes a vet may actually put a senior cat on a kitten diet if weight loss is a major issue, simply to get enough calories into them (8). In milder cases, a more calorie-dense senior food may be the way to go. If your cat has the opposite problem, well, low-calorie is where it’s at. Both obesity and being underweight can cause significant health problems or be symptoms of them, so keep a close eye on the body condition of older cats. If something changes, always have a vet check for disease before trying to treat the problem with diet alone.

There are other variables as well, such as dietary phosphorous and sodium, which sometimes matter for senior cats if they have certain health problems (9). If your cat has any health issues but they don’t require a medical diet, ask your veterinarian if there is anything you should be on the lookout for when choosing their food.

All Life Stages Cat Food

In order for a pet food to claim that it is “complete and balanced” for all life stages, it must meet the standards set by the AAFCO for both the growth and reproduction and adult maintenance stages. Because the minimums for certain nutrients are higher in the growth/reproduction stage, and there are only a few maximums, “all life stages” food may be too nutrient-dense for some adult cats (12). The food has to have enough nutrients for every stage of life, so it makes sense that what you end up with is more like the food intended for kittens and queens. They have higher nutrient requirements.

Opinions are divided, but I found that veterinarians seemed most inclined to think that food for all life stages was really not appropriate for adult or senior cats (12, 13). Pet food companies had the more mixed advice. Personally, I think all life stages food is great for keeping on hand if you find a stray cat or kitten you need to assist, as you never know what age they might be, and the extra nutrients are probably not a bad idea. It’s not what I would feed my cats at home, though.

Works Cited

  1. Paretts, S. (n.d.). What is the difference between kitten and cat food? The Nest. https://pets.thenest.com/difference-between-kitten-cat-food-6832.html
  2. ASPCA. (n.d.). Cat nutrition tips. link here
  3. John, B. (2019, November 19). Kitten food vs. adult cat food: What are the differences? IdleCat. https://theidlecat.com/kitten-food-differences/
  4. Association of American Feed Control Officials. (2014). AAFCO methods for substantiating nutritional adequacy of dog and cat foods: Proposed revisions edited per comments for 2014 official publication. PDF
  5. Syufy, F. (2019, November 4). How to choose the best kitten food. The Spruce Pets. https://www.thesprucepets.com/choosing-best-kitten-food-552267
  6. US Food and Drug Administration. (2020, February 28). “Complete and balanced” pet food. link here
  7. Chewy Pet Central. (2019, November 13). Cat food for all ages: How (and what) to feed your cat during every stage of life. https://petcentral.chewy.com/ages-stages-cat-food/
  8. Chewy Pet Central. (2019, December 10). The best senior cat food: A guide to feeding your older cat. https://petcentral.chewy.com/best-senior-cat-food/
  9. Freeman, L.M., Linder, D.E., and Heinze, C.R. (2016, March 8). When should I switch my pet to a senior diet? Tufts Clinical Nutrition Service. https://vetnutrition.tufts.edu/2016/03/when-should-i-switch-my-pet-to-a-senior-diet/
  10. Pittari, J., et al. (2009). American Association of Feline Practitioners: Senior care guidelines. Journal of Feline Medicine and Surgery, 11(9), 763-778. https://doi.org/10.1016/j.jfms.2009.07.011
  11. PetCoach. (n.d.). Do senior cats have different nutritional needs? https://www.petcoach.co/article/nutritional-needs-of-senior-cats/
  12. Coates, J. (2014, April 25). Are life stage dog foods credible? PetMD. https://www.petmd.com/blogs/nutritionnuggets/dr-coates/2014/april/debate-over-all-life-stage-dog-foods-31604
  13. Rock Veterinary Clinic. (n.d.). Understanding pet food labels. https://www.rockvetclinic.org/post/understanding-pet-food-labels.html

Published July 26th, 2020

Updated November 1st, 2020

Cat Care

In Search of the Best Cat Food, Part II: Wet or Dry?

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mehshadoweye

Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

White cat eating dry cat food
Image by Deedee86 from Pixabay

There is a head-spinning variety of cat foods out there, but the most basic distinctions can be drawn based on moisture content. Dry cat food, the familiar dehydrated kibble, contains 6-10% water (1, 2). Semi-moist food is 15-30% water (2). Canned food has a moisture content of at least 75% (1, 2). Generally speaking, the higher the moisture content, the higher the price and the lower the convenience, so dry food is a very popular choice. But is it the best choice for our cats’ health?

Because kibble is already dehydrated, it doesn’t dry out if left in the bowl for long periods of time, so it lends itself to the convenience of free-feeding. Cats usually like to eat lots of small meals, and let’s face it, people like to be lazy, so this arrangement is often mutually agreeable. We’ll discuss in another part of this series why free-feeding may not be ideal, at least for some cats, but regardless it is often what busy people resort to, and dry food makes that easy. Dry food can also be bought in bulk and will last a long time if stored properly in a cool, dry place. And, again, it’s usually cheap.

Human concerns are not the only reason why someone would feed their cat dry food, however. It has long been thought that kibble helps clean cats’ teeth, preventing and/or treating dental disease. Veterinarians sometimes recommend it for this purpose (3). The idea is that chewing the hard bits of kibble mechanically scrapes the teeth clean of plaque buildup (3), and there has been some scientific evidence supporting the idea that dry food does, in fact, prevent periodontal disease (4). More widely, however, the evidence does not support the idea that dry food cleans cats’ teeth, and there is good reason why it wouldn’t (3).

As mentioned in part one, cats are obligate carnivores. They evolved to eat meat exclusively. As such, their teeth are made for biting and tearing, not chewing (3). Plant matter includes tough cell walls that need to be broken down, so animals that are meant to eat plants do a lot of chewing (3). Carnivores just bite off manageable chunks and swallow them whole (3, 5). That is usually what cats do with kibble. They swallow it whole. Sometimes they bite the kibble, but when they do, the hard but brittle kibble shatters on the biting edges of the teeth and doesn’t do anything to scrape the teeth clean (3, 6).

Yawning gray tabby cat
These chompers aren’t for chewing – Image by Martina Misar-Tummelsthammer from Pixabay

As far as the nutrition of dry food goes, it isn’t great news, either. Dry cat food is typically high in carbohydrates, on average 35-50% by calories (6). Cats neither need carbohydrates, nor can they digest them well, due to their biology as obligate carnivores. They need a diet high in animal protein with a moderate amount of fat (see part one).

Not all dry foods are created equal, of course, but even grain-free dry foods can still be high in carbohydrates if they simply replace grains with potatoes or peas (6). It’s also common for much of the protein in dry food to come from plant matter, but plant proteins do not contain all of the amino acids that cats need (6). The missing nutrients are supposed to be added back in, otherwise the food won’t meet required nutrition standards, but pet nutritionists are still learning exactly what cats need.

With all that being said, is dry cat food just the worst? Well, no, trying to make a cat vegan or feeding them a diet of human food would probably be the worst. When I looked up veterinarian opinions on whether dry or wet food was better, there were mixed opinions. Some were adamant that cats should only be fed canned/wet food (i.e. 3, 6). Others said it didn’t matter (i.e. 5), or it depended upon the cat. I didn’t come across anyone who was a staunch defender of dry food, but there were definitely professionals who had no quarrel with it. I’ll touch on semi-moist food at the end, since it is kind of a weird middle ground, but first let’s take a look at wet food.

Wet food, which as far as I know only comes in cans, can vary in quality but is always notable for its high water content, up to 84% (7). Cats should consume about 20-70 ml of water per kg of body weight per day (8). But cats are descended from Felis lybica, a desert wildcat, so they have a low thirst drive. They tend to obtain most of their water from their food. Prey would normally contain 70-75% water (6). Studies have demonstrated that cats can avoid dehydration without drinking any water at all as long as they are given food with at least 67% moisture content (7, 9, 10).

Of course, a cat should never be without fresh water, but it goes to show just how important dietary water is to cats. Canned food replicates the water content of prey well and helps keep cats hydrated. This prevents urinary and kidney problems, which are common in cats and can be very dangerous (3, 5, 6, 11). Cats fed dry food will drink more water, but they don’t drink enough to compensate, resulting in dehydration and possibly health problems (6).

Canned food is usually higher in protein and made with more animal ingredients than dry food, although cheap, low-quality canned food may still be more plant-based. Reading labels is important, even though pet food labels are not as informative as human food labels. When doing so, keep in mind that the amounts of nutrients are listed as percentages, so the more moisture a food has, the less of other nutrients it may seem to have. Some math may be required to determine the comparative dry weight nutrient content.

Calico cat drinking from garden pool
Cats need to get most of their water from their food – Photo by Dorothea OLDANI on Unsplash

Canned food isn’t perfect. A positive correlation has been demonstrated in cats between hyperthyroidism and eating canned food (5, 12). The cause of the correlation is unknown, although there are a number of theories, one of which suggests that the actual cause is a fire-retardant chemical present mostly in indoor fabrics, not the food (13). However, until we know more, all that can be said for sure is that a correlation has been found.

Semi-moist food comes in plastic pouches or trays, which often aren’t recyclable, so I have to say it isn’t my preference just because of the environmental impact of all that plastic. However, semi-moist food provides cats with quite a bit more water than dry food while not going bad in the bowl as quickly as wet food, so it can be a good compromise between a cat’s need for dietary water a human’s busy schedule. Semi-moist food tends to feature animal ingredients as the main event, providing more protein and a more species-appropriate dish than many dry foods (1). Those pouches and trays are pre-portioned and easy to dump in the bowl, but do be careful that the portion it comes in is right for your cat if you choose this option.

Because cats are the domesticated version of a desert animal, dietary water is extremely important. If for this reason and no other, canned food, ideally a high-quality, meat-forward one, would be the best option. Not everyone can afford the most expensive, gourmet canned food, however. Cheap canned food or semi-moist food is still a good option. A 2010 study showed that cats exhibited better urinary health if water was simply added to their dry food (11). We all have to figure out the best plan for ourselves and our cats. If your cat has specific dietary needs, and you aren’t sure how that would affect what form of food would be best for them, it’s always a good idea to ask your veterinarian.

Works Cited

  1. Cornell Feline Health Center. (2017, July). Feeding your cat. Cornell University College of Veterinary Medicine. Retrieved here.
  2. Feuer, D. (2006). Your Cat’s Nutritional Needs. National Research Council.
  3. Kelsey, A. (2014). 6 reasons why dry food does not clean your cat’s teeth. Cat Behaviourist. http://www.catbehaviourist.com/blog/6-reasons-dry-food-clean-cats-teeth/
  4. Watson, A.D. (1994). Diet and periodontal disease in dogs and cats. Australian Veterinary Journal, 71(10), 313-318. DOI: 10.1111/j.1751-0813.1994.tb00905.x
  5. Barchas, E. (2017, July 31). Ask a vet: Would you recommend wet food or dry food for cats? Catster. https://www.catster.com/lifestyle/wet-dry-cat-health-canned-food-kibble-cats-ask-a-vet
  6. Pierson, L.A. (2016, November). Feeding your cat: Know the basics of feline nutrition. CatInfo.org. https://catinfo.org/
  7. Case, L.P., et al (1995). Canine and feline nutrition. Mosby, Inc.
  8. Ackerman, N. (Ed.). (2016) Aspinall’s complete textbook of veterinary nursing, 3rd edition. Elsevier.
  9. Prentiss, P.G., Wolf, A.V., Eddy, H.A. (1959). Hydropenia in cat and dog. Ability of the cat to meet its water requirements solely from a diet of fish or meat. American Journal of Physiology, 196(3), 625-632. https://doi.org/10.1152/ajplegacy.1959.196.3.625
  10. Caldwell, G.T. (1931). Studies in water metabolism of the cat. The influence of dehydration on blood concentration, thermoregulation, respiratory exchange, and metabolic-water production. Physiological Zoology, 4(2), 324-359. Retrieved from https://www.jstor.org/stable/30151145
  11. Waltham Petcare Science Institute. (n.d.) Cats benefit from increased dietary moisture. https://www.waltham.com/news-events/nutrition/cats-benefit-from-increased-dietary-moisture/5548/
  12. Edinboro, C.H., et al. (2004). Epidemiologic study of relationships between consumption of commercial canned food and risk of hyperthyroidism in cats. Journal of the American Veterinary Medical Association, 224(6), 879-886. DOI: 10.2460/javma.2004.224.879
  13. Hofve, J. (n.d.) Feline hyperthyroidism. Jackson Galaxy. https://www.jacksongalaxy.com/blog/feline-hyperthyroidism/

Published July 12th, 2020

Updated November 21st, 2020

Cat Care

In Search of the Best Cat Food, Part I: Feline Nutrition

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Meredith Hemphill

mehshadoweye

Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

Brown tabby eating out of bowl
Photo by Hans Reniers on Unsplash

Today I am trying something new on this blog. Almost anyone with a pet has asked the question, “What is the best food to give them?” Even after asking the advice of my veterinarian what to feed my cat, I still felt pretty lost and confused. I am undertaking a series of articles in which I aim to gather as much information as I can about feline nutrition and what difference the many kinds of cat food really make on a cat’s well-being.

The series will have five parts: feline nutrition, wet vs. dry food, diets for different life stages, specialty diets, and indoor diets. I will be interspersing other articles during this series so that it doesn’t get boring. Feel free to comment with your own questions about cat food, and I will look into them.

Of Carnivores and Calories

To begin with, I thought it would be helpful to go over the basic facts of feline nutrition. The fundamental elements of an animal’s diet, humans included, are very simply broken down into protein, fat, carbohydrates, vitamins, and minerals. Cats of all kinds are obligate carnivores. That means that they have evolved to eat only meat, and they are not well-equipped to derive nutrition from plant sources. This has a major impact on their nutritional needs.

The amount of calories a cat needs per day depends upon their age, activity level, health, and whether or not they have been sterilized. Growing kittens and pregnant or nursing queens need significantly more energy. Intact adults need a bit more than neutered adults. An eight-pound adult cat needs about 240 kcal (kilocalories, or what we usually just call calories) each day [1]. The Animal Medical Center of Chicago has a very helpful chart for getting a good idea of how many calories your cat or kitten is likely to need, which you can download a copy of below [2]. Because cats have evolved to eat only meat, their bodies are designed to obtain these calories primarily, if not exclusively, from proteins and fats.

Calorie Requirements For CatsDownload

Macronutrients in Feline Nutrition

Carbohydrates and Proteins

Obligate carnivores require a high protein, moderate fat, low carbohydrate diet to be their healthiest. Carbohydrates, which are plentiful in plant matter, can be difficult for cats to digest and are not necessary in the feline diet [3]. Instead of deriving most of their energy from carbohydrates, as humans do, cats use protein as their primary source of energy [4, 5]. A nine-pound cat with a 250 kcal-per-day diet is recommended to receive 12.5 grams of protein each day [3]. It isn’t just the amount of protein that matters, however. Proteins are made of molecules called amino acids. There are 23 amino acids. Cats can manufacture some of these themselves, but there are 11 that they must get from their diet [6, 7]. These are known as essential amino acids. The essential amino acids for cats are:

Black and white cat watching mouse
Some cats are fiercer hunters than others, but all are obligate carnivores – Image by Erika Stockenhofen from Pixabay
  • Arginine
  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Taurine
  • Threonine
  • Tryptophan
  • Valine

Taurine is an unusual requirement particular to cats, but it is very important. A taurine deficiency can lead to blindness, deafness, heart problems, and loss of kittens or congenital defects with pregnant queens [3, 7]. Taurine is only present in animal protein, a callback to the nature of cats as obligate carnivores [7].

Fats

Cats also have rather specific needs when it comes to the fats in their diets. We have a tendency to think of fat as a dirty word, but fats serve very important functions in the body, in appropriate quantities. Fats are an important source of energy, they provide insulation to nerve fibers and protection to internal organs, they aid in absorption of the fat soluble vitamins, and they are critical for cell structure and function [3, 6, 7]. Cats can tolerate fairly high amounts of dietary fat since it is such an important energy source for them [3]. The average cat we used as an example before has a recommended daily allowance of 5.5 grams of fat [3].

Fats are composed of fatty acids, and like amino acids, some of these can be made in the body, and some cannot. Science is still learning which fatty acids are essential for cats, but some things are well-known. Cats are unable to manufacture arachidonic acid, an important precursor molecule with end products that have wide range of functions in the body [6]. Arachidonic acid is found only in animal fat [7]. Linoleic acid is an essential fatty acid for all animals [7]. DHA is a fatty acid that has been shown to be important for the neural development of kittens, so it may be necessary for reproducing queens and young, weaned kittens [6, 7].

Micronutrients in Feline Nutrition

Now, let’s talk micronutrients. Vitamins are organic nutrients, manufactured by a lifeform somewhere in the food chain. Minerals are inorganic nutrients that come from the environment. Cats need Vitamins A, D, E, K, and the B complex [3, 6, 7]. They have no need for dietary Vitamin C, as they are able to make that for themselves [6, 7]. Minerals are a bit trickier, since some of them are needed in very small amounts but are still absolutely critical. The US National Research Council considers twelve minerals essential for cats [3], but I included a thirteenth from another source as well [6].

Vitamins

Five eggs
Photo by 青 晨 on Unsplash

Vitamin A is a big one for cats. Some animals can make Vitamin A from precursors in plants, like beta-carotene, but cats can’t do that [7, 8]. They have to consume Vitamin A in its completed form from animal sources [7, 8]. Vitamin A is important for vision–especially night vision, healthy skin and mucous membranes, and normal bone and tooth growth [6, 7]. Fish oil, liver, eggs, and dairy are natural sources of Vitamin A [6, 7].

Vitamin D is needed for the body to use calcium and phosphorous [6, 7]. Cats can synthesize it in their skin in the presence of UV light, but not very well, so dietary Vitamin D is important [6]. It can be found in marine fish and fish oils, liver, and egg yolks [6, 7]. Vitamin E is an antioxidant synthesized by plants but present in small amounts in animal sources [6]. The amount a cat needs depends upon how much oxidative stress their body is under [6, 7]. Vitamin K is important for blood clotting, but healthy cats are able to synthesize enough of it on their own [6, 7]. If the intestinal bacteria that normally make Vitamin K are decreased, perhaps if the pet is on antibiotics, dietary Vitamin K can become important [6]. In that case, fish meal, egg, and liver can be good sources [6].

There are eight B vitamins, which are necessary for energy metabolism and making healthy tissues [6]. Because they are soluble in water, it is uncommon for a cat to get too much of a B vitamin. The excess just washes out in the urine [7]. Cats usually get enough B vitamins from their food, but while most animals can synthesize niacin, or B3, cats can’t and must get it from their diet [6]. Fortunately, meat is a good source of niacin [6]. The other B vitamins can come from eggs, organ meats, or muscle meat, depending on the B vitamin in question [6].

Minerals

Salmon steak
Salmon is a good, species-appropriate source of potassium – Image by congerdesign from Pixabay

We have a bunch of minerals to get through, and I would feel like I wasn’t providing the most complete information if I left any out. But I don’t think anyone wants this article to go on for twenty pages, so I’m going to summarize the main reasons each mineral is important and where cats get the minerals from in their diet [3, 6, 7].

  • Calcium for skeletal and muscular health: poultry/meat meals, bone
  • Phosphorous for skeletal health and energy metabolism: meat, poultry, fish
  • Magnesium for muscle, nerve, and hormone function: bone meal
  • Sodium for homeostasis and nerve function: fish, poultry meal, eggs
  • Potassium for nerve and enzyme function: fish, especially salmon [9]
  • Chloride for homeostasis: fish, poultry meal, eggs
  • Iron for red blood cells and energy metabolism: meat, organ meat
  • Copper for tissue synthesis: organ meat
  • Zinc for cell growth and wound healing: beef liver, dark poultry meat, egg yolks
  • Manganese for bone growth and neurological health: meat, poultry, fish
  • Selenium for antioxidant activity and immune health: meat, poultry
  • Iodine for thyroid function: meat, poultry
  • Sulfur for protein synthesis: meat, poultry, fish

Moving Forward

What do we do with this information? Out of curiosity, I grabbed one of Joon’s cat food cans to see how much of this information is actually available on the label. What I found was a section giving the crude protein, crude fat, crude fiber, moisture, “ash,” calcium, phosphorous, magnesium, and taurine content in either minimum or maximum percentages. Ash is a term sometimes used to refer to mineral content [6]. Below that, the kcal per can and per kilogram (of this food that comes in 170-gram cans) was given. That gives me the ability to calculate the gram values of the nutrients, although it’s frustrating that I have to. And then there’s the brief feeding instructions, with the ingredients on another panel.

It’s less information than I would have hoped for, and it’s presented much less plainly than on human food labels here in the US. So I tried one of the cans of prescription food we give my parents’ elderly cat. I thought maybe it was just the company I buy Joon’s food from. Nope, Rosie’s food had even less information on it. There were no percentages for minerals at all.

As we continue with this series, I’ll delve into different types of food and what it all means. What looking at the back of this can is telling me right now, however, is that as pet parents we need to be as informed as we can. Evidently, no one is going to hand the information we need about feline nutrition to us. At least, not anybody in the pet food aisle. If I look at the ingredients, I can see that this food has a lot of added nutrients and ingredients that provide them naturally, but a few hours ago I wouldn’t have known that including tuna and fish oil in a chicken-flavored food can provide nutrients that the chicken alone might not. The more we know, the better prepared we are to make the best decisions possible for our cats.

Works Cited

  1. How many calories should your dog or cat eat daily? (2014, April 25). Dunloggin Veterinary Hospital. https://dunlogginvet.com/how-many-calories-should-your-dog-or-cat-eat-daily/
  2. Calorie Requirements for Cats (n.d.). Animal Medical Center of Chicago. https://www.animalmedicalcenterofchicago.com/cat-diet-calorie-requirements-for-cats/
  3. Feuer, D. (2006). Your Cat’s Nutritional Needs. National Research Council.
  4. Optimum feline nutrition: what should you feed your cat? And feline weight loss and prevention plan. (n.d.). Cat Care Center of Baton Rouge. https://www.catcarecenter.com/services/cats/feline-nutrition-cat-food
  5. Llera, R. and Ward, E. (2019). Nutrition: General feeding guidelines for cats. VCA Hospitals. https://vcahospitals.com/know-your-pet/nutrition-feeding-guidelines-for-cats
  6. Case, L.P., et al (1995). Canine and feline nutrition. Mosby, Inc.
  7. Ackerman, N. (Ed.). (2016) Aspinall’s complete textbook of veterinary nursing, 3rd edition. Elsevier.
  8. Schultze, K.R. (2010, February 9). Your cat’s nutritional needs: The basics. Feline Nutrition Foundation. https://feline-nutrition.org/nutrition/your-cats-nutritional-needs-the-basics
  9. Millen, B. et al (2015). Appendix 10: Food sources of potassium. Health.gov. https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/appendix-10/

Published July 5, 2020

Updated June 20, 2022

Cat Care

Should cats drink milk?

mehshadoweye

Meredith Hemphill

mehshadoweye

Encyclopaedia Felidae now has a Patreon! Go to www.patreon.com/EncyclopaediaFelidae if you want to help support this content!

Two tabby cats drinking saucer of milk
Image by FotoRieth from Pixabay

I was recently watching a YouTube video–one of those funny cat compilations, you know the type. One of the clips included a cat being offered milk, and oh boy, did the comments go crazy. Everyone had an opinion about whether cats should drink milk or not. I’ve always heard that cats are lactose intolerant and shouldn’t have milk, but there were lots of people who disagreed. Certainly YouTube comment sections are not the place to obtain scientific information, but it sparked my curiosity. I had no idea there was so much debate about this topic, and now I wanted to find out the answer for myself.

Cats certainly seem to like milk. My parents have had two infamous ice cream thieves. And cats have been portrayed in media of all kinds happily lapping from a saucer of milk, for at least two hundred years and possibly going back to the Middle Ages, but I had some trouble verifying the dates of older images. Why do cats like milk so much, or are we imagining it?

It’s not an illusion. Dairy farmers noticed a long time ago that cats would get very excited about fresh cow’s milk. Cats are particularly fond of the cream that rises to the top of the fresh milk, as cats are naturally drawn to fatty foods that would help them survive in the wild where food is not guaranteed, and cream is certainly high in fat. It has also been demonstrated that cats relax while lapping milk (1), perhaps because it recalls pleasant maternal memories.

Brown and white calf
Intended recipient of cow’s milk – Photo by Couleur on Pexels

Unfortunately, the fact that cats like milk doesn’t mean they should drink it. Kittens drink their mother’s milk in order to gain vital nutrients and antibodies until they begin weaning. The milk of mammals contains a sugar called lactose, and infants produce an enzyme called lactase to break down this sugar which provides them with important energy for their development. As the kittens begin to eat solid food and less of their mother’s milk, they slowly stop producing lactase. The same is true of other mammals, including humans, but an unusual percentage of humans continue to produce enough lactase to digest dairy into adulthood. Cats, like other mammals, usually don’t. This means that most cats are lactose intolerant as adults.

Cats may enjoy milk or other dairy products while they’re eating them, but the majority who are lactose intolerant will pay for it later with gastrointestinal upsets. The undigested lactose can’t be absorbed into the bloodstream, so it moves straight through the intestines, drawing water with it and causing loose stools or diarrhea. They may also experience vomiting, and the action of intestinal bacteria fermenting the lactose can cause gas and bloating. Even cats that are not lactose intolerant may have dairy allergies that can also cause gastrointestinal and/or skin problems (2). Not the recipe for a happy cat, or a happy cat parent, for that matter.

Not all cats have this problem. There are some that can handle milk without an issue. Others are fine with small amounts from time to time but react negatively if given more. Regardless, it’s important to note that cow’s milk is not nutritious for cats even if they can tolerate it. It’s essentially junk food, high in calories but devoid of the protein and other nutrients that cats need. Obesity is a significant problem among pet cats. Whole milk especially poses a risk because it has so much fat. A well-nourished cat doesn’t need all that fat.

White goat
Goat’s milk can be a good treat for some cats – Photo by Ellie Cash on Unsplash

The healthiest cat treats are plain meat, cooked if you’re worried about contamination (which would be fair). Nutritious commercial treats can also be fine in moderation. However, if your cat is just crazy about milk, there are some options that are better for your cat. If you already know that your cat can tolerate lactose, then small amounts (think a teaspoon or so) of low-fat or skim milk as an occasional treat could be fine. Lower-lactose products such as plain yogurt or goat’s milk might also do. Goat’s milk has more vitamins and minerals than cow’s milk and contains the amino acid taurine, which cats require, so there’s a point in favor of the goats.

I have seen some claims that raw (unpasteurized) milk is preferable because the nutrients and enzymes present in the milk have not been heat-killed. I have also seen some information which suggests that it might be dangerous due to the presence of potentially harmful live microorganisms. Personally, I would err on the side of caution and choose pasteurized, but you can make your own decisions in the regard. Lactose-free milk products for humans are available, as well as “cat milk” products specially formulated for cats. They vary, but are generally lactose-free, low-fat, and more nutritious for cats. They are available online and at many pet stores. In any case, milk of whatever sort should be given only as a treat to adult cats, in small amounts.

Milk alternatives that should not be used include plant milks such as soy milk, almond milk, etc. Cats are carnivores and are not well-equipped to digest the carbohydrates in plants. Plant milks are often sweetened, and cats do not need all that sugar, either. Plus, it isn’t uncommon for cats to have allergies to soy.

In settling a great YouTube debate, it seems that cats should generally not drink milk, but there are cats who can handle it or other kinds of milk that cats can have. As long as it’s given as a treat, rather than used as a major part of their diet, a little dairy or an appropriate alternative can be okay. I would rather Rosie stayed out of my ice cream bowl, however.

Note: Kittens should never be given cow’s milk or any kind of alternative. They should only receive their mother’s milk or a kitten formula, if a mother isn’t available, until they are old enough for weaning.

Works Cited

  1. Cervantes, M., Ruelas, R., and Beyer, C. (1983). Serotonergic influences on EEG synchronization induced by milk drinking in the cat. Pharmacology Biochemistry and Behavior, 18(6), 851-55. https://doi.org/10.1016/S0091-3057(83)80004-5
  2. Guilford, W.G., et al. (2001). Food sensitivity in cats with chronic idiopathic gastrointestinal problems. Journal of Veterinary Internal Medicine, 15(1), 7-13. DOI: 10.1892/0891-6640(2001)015<0007:fsicwc>2.3.co;2
  3. Kornreich, B.G. (2020, May 2). Dear Elizabeth: Is feeding cats milk safe for your kitty? [Email newsletter] Cornell Feline Health Center.

Published on May 8, 2020

Updated January 2, 2021