Encouraging your clients to feed their cats the way nature intended helps prevent obesity and other health problems.

We heard it all the way through veterinary school: “Cats are not small dogs!” This is especially true when it comes to feeding them. This article looks at the type of diet cats have evolved to eat, feeding problems that lead to obesity and other issues, and how to help keep your feline patients lean and healthy.

DIETARY ADAPTATIONS

Let’s review some of the ways cats have evolved to consume their natural diet of prey animals:

• Their teeth are adapted to puncturing and shearing, not chewing.
• Feline jaws cannot move side to side.
• Their barbed tongues help rasp every last bit of meat from bones.
• Cats have specific requirements for taurine, arginine, methionine, cysteine, arachidonic acid, vitamin A, vitamin D, niacin, and vitamin B6.
• They can’t convert alpha-linoleic acid into DHA and EPA.
• Cats preferentially use protein and fat for energy.
• Their protein requirement is two to three times higher than that of dogs.
• Cats depend on protein for energy as well as for structural and functional purposes.
• While they can digest and utilize carbohydrates, they are less able to do so than dogs.
• Cats cannot up-regulate this utilization, even when dietary carbs are plentiful.
• They continue to use amino acids for gluconeogenesis, regardless of diet.

BUILD A BETTER MOUSE?

Feeding cats a diet that’s as close as possible to what they evolved to eat is just common sense. Of course, science doesn’t rely on common sense, so someone had to do a study about it. At last, the dietary composition preferred by cats has been discovered! It turns out that cats choose foods that most closely mimic their natural prey: about 55% protein, 40% fat, and 5% carbohydrate on a dry matter basis. This is approximately the same composition as a can of kitten food, or a well-formulated homemade or raw diet. It is also closely in line with the diet of feral cats. Nevertheless, despite our best efforts, there is no way we can actually recreate a mouse, because one very crucial part is missing: blood. Blood is made up of plasma, red blood cells, white blood cells, and platelets. Red blood cells are high in protein, iron, and lipids. Plasma is mostly water, but the solid portion comprises proteins such as albumin, globulins, and clotting factors; amino acids
like taurine and lysine; and 1% mineral salts, sugars, fats, hormones, and vitamins.

When a cat kills a mouse, she eats the whole thing, including the blood. When an animal
is slaughtered for consumption, the first thing that happens is that the blood is drained out of the carcass. The blood is retained, dried, and used for various purposes, such as fertilizer or feed for fish, poultry, and cattle. But by then, it has lost its energetic life force, and is no more than a protein supplement. There is just no way to recapture that lost vitality.

“CHONKY CATS” – NOT CUTE, NOT FUNNY

“Chonky” cats have become quite popular on social media. The latest estimate is that 60% of adult cats are overweight or obese. This can lead to many serious conditions such as arthritis, chronic vomiting and/or diarrhea, allergies, diabetes, skin disease, feline lower urinary tract signs (LUTS), hepatic lipidosis, cancer, and immune system, heart, liver and kidney issues. Preventing obesity is much easier than treating it. It’s on us, as veterinarians, to help our clients get their kittens off to a good start and keep their adult cats on the right track.

Several factors combine to thwart our goals for healthy cats:

DECREASED METABOLIC NEED AFTER NEUTERING

It’s estimated that neutered adults need 25% to 30% fewer calories than intact cats. Those hormones preserve lean muscle and keep activity high. Add to this a less-than-stimulating environment, and there’s the recipe for a fat cat! Environmental enrichment, interactive play, and reduced overall caloric intake (starting around six months of age) will help keep cats mentally and physically fit.

EXCESS CARBOHYDRATES

Most dry cat foods are 30% to 50% carbohydrate. Cats have zero physiologic need for carbs. Dietary carbohydrate that is not stored as muscle glycogen or used for immediate energy needs is stored as fat. High-fiber weight loss diets increase dehydration and reduce protein digestibility. The loss of lean body mass and reduced basal metabolic rate that
occurs with weight loss make it more likely the cat will stop losing weight — or even regain it — even on the same reduced-calorie food.

CONSTANT FOOD AVAILABILITY

Cats are not — and should not be — grazing animals. Too many people not only feed dry food, but leave it out around the clock, every day. A hunting cat will kill eight or nine
mice in a 24-hour period, so multiple small meals makes some sense. But cats who are allowed constant access to dry food eat 15 to 20 times per day. Pet food manufacturers are very good at making those blah kibbles irresistible by spraying them with fat and animal digest (often called “natural flavor” on labels). So cats keep eating, and eating.

Issues for 2022: Sustainability

The pet food industry uses the leftovers and wastes of human food processing to create many of the products our clients buy and feed to their cats. This is actually a plus for sustainability. It effectively “recycles” the 30% to 50% of every food animal that people don’t eat. About half of every cow, and more than a third of the live weight of every pig and chicken, go unconsumed. Using non-human-edible animal parts for pet food seems more sustainable.

However, most analyses of pet food sustainability do not consider other important factors. One is pet waste. Cats and dogs eating a raw meat-based, highly-digestible diet produce much less fecal waste. They are also healthier, and therefore less likely to be given
pharmaceuticals that can end up in groundwater.

People who are conscientiously eating and feeding sustainably and regeneratively farmed meats and plants are mitigating the pollution and other negative effects of factory farming.

Plant products are not necessarily as earth-friendly as pet food makers want you to think. Corn and rice use tremendous amounts of fresh water. The machinery used for growing and harvesting crops depends on fossil fuel. Agricultural chemicals are harmful to the environment. While many of us avoid GMOs, the herbicide glyphosate (the main ingredient in Roundup®) is sprayed on many non-GMO crops to dry them out and make for a more uniform harvest. Legumes, potatoes, and other plants commonly used in pet foods are more heavily contaminated with glyphosate than GMO products themselves. (Legumes and potatoes…why does that ring a bell? Oh yes, those were the exact products the FDA wrongly suggested were causing dilated cardiomyopathy! Glyphosate, meanwhile, has negative impacts on the microbiome…could that be the link they were looking for?)

There are two alternative proteins on the horizon that may help make healthy, species-appropriate cat food more available and sustainable.

INSECT PROTEINS

Cats eat bugs. Sometimes they eat a lot of bugs. Insects, particularly insect larvae (grubs) are quite nutritious. Insects produce a lot of protein in far less space, and at far less cost in
resources, than factory-farmed cows. Crickets and ants are even high in taurine, which may help reduce reliance on the synthetic taurine currently added to cat foods. Many pet foods and treats featuring insect proteins are already on the market. Currently, only black soldier fly larvae (Hermetia illucens) are legal in pet food, and then only in dog food. But that’s not stopping dozens of companies from using them in cat food, as well as crickets
and other grubs in many other pet products.

CULTURED MEAT

Most people, when asked about lab-grown meat, respond with “eww!” But there are many advantages, from the immense reduction in resources used to grow it, to the complete absence of factory farms and animal slaughter. How healthy it is will depend on the original animals the cells are harvested from, and what goes into the culture medium that grows it. But it’s easy to foresee completely organic, environmentally safe, pathogen-free meat in our cats’ bowls. As a common food, it’s likely years in the future, but at least one company plans to release its first cultured meat pet foods this year.

KEEPING CATS LEAN AND HEALTHY

Feed high-protein, high-moisture, very low-carbohydrate food, and eliminate dry food. A balanced homemade or commercial raw diet are best for clients who are able to go that route. Reconstituted freeze-dried and dehydrated foods are also good, but watch the carbs! One very popular dehydrated diet clocks in at more than 47% carbohydrate! For many clients, canned foods are a reasonable substitute, especially if digestive enzymes and probiotics are added. Cats on a high-protein, low-carb diet — similar in composition to
prey — are less liable to gain excess weight. If they need to lose weight, such a diet helps them retain lean body mass.

Feed in timed meals; if possible, feed more small meals. Food should be provided for 30 to 60 minutes at a time, and removed at all other times. Most people can accommodate a three-meal-a-day schedule for their cats: morning, after school or work, and before bed. A
good interactive play session followed by the evening meal also helps cats who tend to get the 4 am zoomies or want breakfast at the crack of dawn to sleep through the night. Cats figure out the schedule very quickly. You can also reassure people that their cats will not starve if they are late coming home from work.

Educating clients about the type of diet cats have evolved to eat, and recommending ways for them to provide high-protein, low-carb foods, will provide a great service to your overweight feline patients, while helping keep lean ones healthy throughout their lives.