Photo by Natalie Rowe
Cats are Carnivores
Unlike dogs and humans, which are omnivores and gain nutrition from both plants and meat, cats are carnivores and primarily get all of their nutrients from animal products. Scientific studies have shown that when cats in the wild live on prey (i.e., animals, such as mice, that they hunt and kill), their diet is primarily protein (55%), some fat (45%), and only 1-2% carbohydrates. The reason for this is that the methods by which cats’ bodies break down and metabolize foods are not suited for digesting starches and sugars. Thus, if they eat a diet high in carbohydrates, they can’t break down and absorb those nutrients nearly as well as a diet higher in animal protein.
All Meats are not Equal
Some researchers advocate avoiding fish-based diets for cats because of potential risk for thyroid disease. Fish-based diets can also lead to extreme food favoritism, preventing you from switching to any other kind of diet in the future. Fish-based diets can sometimes have an imbalance of phosphorus and magnesium. Feeding canned tuna exclusively to cats can also cause vitamin E deficiency.
Additional Nutritional Needs of a Cat
In addition to cats’ protein requirements, they are also deficient and/or can’t make certain amino acids and nutrients needed for their survival. Thus, it is necessary for cats to get them from food. These include the amino acids arginine, taurine, methionine, and cysteine, as well as vitamins such as vitamin B (niacin) and vitamin D. When researching commercial cat foods, it is important to ensure these are part of the ingredients. Many of these important amino acids and nutrients are primarily obtained from animal products (e.g., liver, protein, fat) which further highlights the importance of a diet high in animal protein. If you are unsure if your cat’s current diet contains these nutrients, ask your veterinarian.
Another way cats tend to differ in nutritional needs is their water intake. The domestic house cat is believed to be descended from wild desert cats. They can survive on less water than some other animals, such as dogs. This is great for survival, but can be a problem long term because they have less of a drive to seek water when their body needs it. This lack of water can lead to a variety of issues over time. For example, if cats don’t get enough water, they produce urine that is more concentrated with the body’s waste materials, and this can lead to problems such as urinary tract issues (e.g., feline lower urinary tract disease, FLUTD, idiopathic cystitis).
This information leads many researchers to recommend canned food because of its higher water content (70%-80% water) over dry food (10%-12% water). Other ways to ensure your cat gets enough water include offering more options for drinking, such as multiple water bowls throughout the house, a kitty water fountain, or letting a faucet drip on occasion to entice them to drink.
Canned Food vs Dry Kibble
Overwhelmingly, research points to a recommendation of canned commercial diets (wet food), high in protein and low in carbohydrates, as the best type of diet. Veterinarians have also frequently noted that common issues in feline medicine such as urinary tract disease and chronic gastrointestinal (GI) issues are much more frequently seen in cats on dry diets.
Another benefit of canned food over dry is that the water content helps maintain the sensation of feeling full, so your cat won’t consume too many calories. Many vets will switch an overweight cat eating dry food to canned food as the first step toward weight loss.
Raw diets aren’t ideal for any pet, even for the carnivorous cat. It is difficult to formulate a raw diet properly to ensure all necessary nutrients, vitamins, amino acids, proteins, fats, and carbohydrates are balanced correctly. Raw meat can also contain bacteria and parasites that can make not only your cat sick, but you as well (e.g., Salmonella). Outdoor and feral cats that eat only prey animals may have a slightly decreased risk of this issue because the kill is fresh, but they can still catch diseases such as toxoplasmosis from eating raw prey. Most name-brand commercial diets have done a significant amount of testing and research to ensure the food is well balanced and appropriate for a pet. Your veterinarian will likely have diet suggestions that would work for your cat.
When to Feed
Many feline species found in the wild tend to be grazers, eating multiple small meals throughout the day and night. This tendency is thought to be associated with the types of prey they hunt. Domestic cats are exactly the same, even if they are eating commercial cat food. Leaving an appropriate amount of dry food out all day so that cats can eat as they need to works pretty well for most cats. If using canned food, or if your cat is on a calorie-restricted diet, if you can offer smaller more frequent meals throughout the day to help keep them on their body’s natural schedule.
How Much to Feed
How much to feed depends on what you are feeding. Many commercial cat foods have a list on the can or bag describing the recommended amount per weight, such as “for a 10 lb cat, feed X cups/cans a day”). Make sure you are feeding the amount your cat needs for a healthy weight, not what the cat currently weighs; if your cat weighs 17 lbs but should weigh 12 lb, feed her the amount for a 12 lb cat). Be sure to use a measuring cup rather than estimating the amount. Feeding just 10 extra pieces of dry kibble a day can contribute to 10% weight gain a year, which is equivalent in most cats to an entire pound of body weight gained in a year!
Keep in mind that feeding an appropriate amount of food will not stop hunting behaviors. This is because in the wild, hunting often requires numerous attempts before success, so the instinct to hunt tends to be separate from a feeling of fullness.
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Always discuss your cat’s nutrition concerns with your veterinarian. Veterinarians are trained in nutrition and understand the delicate balance of nutrients needed to keep a pet healthy. Your veterinarian can make food recommendations based on your pet’s personal physical examination and health status. Most veterinarians keep up to date on pet food changes and issues, so they should be able to provide you with several options and choices from multiple pet food companies.
Another way to help ensure your cat is eating a quality commercial diet is to check if the food is formulated to meet the standards of the Association of American Feed Control Officials. AAFCO publishes yearly standards and guidelines to help maintain the nutritional appropriateness of pet foods. These standards and guidelines are created through scientific evaluation and testing. AAFCO is not a government regulatory body, but it is made up of state and government officials. Unfortunately, these standards cannot be used to certify or approve pet foods, but they are a good way to get a general idea of the food’s adequacy as a diet.
Avoiding a Picky Eater
Not surprisingly, cats tend to develop preferences for certain textures, flavors, smells, and temperatures of food. Preferences are fine, but extreme pickiness can make changing diets or getting a sick cat to eat difficult. Consider offering high-quality cat food options to your cat in early adulthood to help avoid becoming stuck on certain options.
Tips for helping a picky eater transition to new foods include:
- Maintain a safe space for your cat to eat (low noise, no concern with other pets trying to eat the food or bother your cat while eating).
- Ensure a picky appetite is not a poor appetite because of illness (e.g., nausea from stomach upset, pain from arthritis).
- Consider warming wet food to enhance smell and taste, but make sure it’s not too hot- cats probably favor this because warmed food mimics fresh prey.
- Mix the old food with the new food and transition slowly.
- Cats often refuse new diets when stressed but will eat them under normal conditions so ensure a stress-free atmosphere during the transition.
Medical Management through Food
Certain prescription and commercial diets have been formulated to address medical problems in cats. Some medical disorders that can be helped with specific diets include renal or kidney disease, dental disease, thyroid disease, diabetes, urinary tract disorders, gastrointestinal diseases, and pancreatitis. If your cat is experiencing a medical illness, especially one that is chronic or ongoing, talk to your veterinarian about whether a prescription diet might be helpful.
Using Food Behaviors to Enhance Daily Life
Food can also help cats, especially indoor cats, express their predatory impulses and live a happier, less stressful, and more cat-like life. This can be done by hiding meals in food puzzles or feeding toys to stimulate their natural predatory instincts of hunting for food. If a cat is on a restricted diet, you can use toys that stimulate the cat’s predator response such as small, mouse-sized toys that squeak or make high-pitched noises. Toys that move in an unpredictable manner are especially fun for cats. This type of feeding or playing can help increase your cat’s activity, decrease their stress level, and may help keep them more physically fit.
Common Myths about Food
While many misconceptions exist about cats and food, a few common ones are listed below. You already know the most important one, that cats are carnivores, not omnivores.
One interesting misconception is about taste. Believe it or not, cats are not capable of tasting sweet flavors. That type of flavor is not part of the chemical receptors in their taste buds. This is likely associated with them being carnivorous as very few animal products or by-products are sweet, so they likely just don’t need the flavor profile.
Another common misconception is about milk. Many adult cats are lactose intolerant. They usually develop this intolerance after maturity. Even small sips of any kind of milk or small bites of cheese can cause stomach issues, loose stool, and excess gas.
Lastly, dry kibble does not significantly reduce the risk of dental tartar and dental disease. The only real way to prevent dental tartar is to brush your cat’s teeth every single day. Thus, if you are avoiding switching to wet food to help keep your cat’s teeth healthy, no worries! If you are still concerned, offer crunchy dental treats as an alternative.
Bottom Line: Feed Canned High Protein, Low Carbohydrate Diets
Cats are not like humans or dogs. They are carnivores and are adapted to eat a diet high in protein whenever possible. Their overall health can be significantly improved if this high protein diet is in the form of canned food to help maintain good hydration. Talk to your veterinarian about switching diets and ask which diet is most highly recommended for your pet.
VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email firstname.lastname@example.org.