Open Letter to Veterinary Professionals About Cat Nutrition

Have you ever seen a barn cat barbecue and dehydrate its mouse dinner and top it off with a dessert of corn gluten meal soufflé? Or heard of a cat that went hunting for rice grains or oatmeal for breakfast? No? It would be illogical to feed an obligate carnivore a steady diet of meat-flavored cereal, right? Then why are we continuing to feed cats like they’re herbivores? I’m hoping many of you read the “Timely Topics in Nutrition” article in the December 1st 2002 Journal of the American Veterinary Medical Association (JAVMA) titled “The Carnivore Connection to Nutrition in Cats.” After reading this article, published over 20 years ago, I wonder how anyone continues to advocate feeding grain-packed commercially prepared dry food to a cat. In the years since, evidence continues to accumulate suggesting that dry food is entirely unsuitable for cats.

Dr. Zoran’s article detailed scientifically what those of us who have been feeding cats what Mother Nature intended for years already deduced from plain common sense: that cats are obligate (true) carnivores and that their metabolic distinctions mean that there are foods that support health and other foods that don’t. If you do nothing else besides read this far into this letter, please go read that article. I’ll wager that if logic prevails, you will never again prescribe or condone feeding a heavily grain-based dry food diet to your feline patients.

Every veterinarian sees obese cats, cats in kidney failure, cats with painful cystitis, bladder stones, inflammatory bowel disease (IBD), diabetes, and cats with hepatic lipidosis. After you read that JAVMA article, it’s impossible to not see the connection between how we are feeding obligate carnivores and many of the diseases that afflict them.

How many times have you heard your clients say, “But Doctor, I only feed Fluffy a very small amount of the feline-maintenance light dry food and she’s still fat!”? I would venture a guess that the inappropriately high carbohydrate level in these “light” foods is the main culprit.

I’d like to see better nutritional counseling of clients by veterinarians. At the very least, their clients would be well served by having their vets counsel their clients to feed a high quality meat-based, high moisture content canned food instead of a carbohydrate-laden, low moisture content dry food. But this will require you to educate your clients on basic label reading. It would be terrific if, as a standard part of every first visit to a veterinarian, the doctor could give their client an easy-to-understand tutorial, accompanied perhaps with a handout to take home, about the practical considerations related to the fact that their cat is a carnivore. And then teach them what to look for on the label in order to seek out, at a minimum, a food that is not dry, contains high-quality meat as a first ingredient, and is not front-loaded with grains, fillers or byproducts. The bulk of commercial cat foods out there today – most especially those that market heavily to veterinary offices – are crammed with carbohydrate-dense fillers that have no place in a proper diet for an obligate carnivore. We simply have to stop feeding so many grains to carnivores. It’s making them sick.

Why should a veterinary professional bother reading anything from a lay person about feline nutrition?

Fair question. I’m hopeful that some of my lay insights into treating one terrible malady and the lessons I’ve learned along the way about feline nutrition might be instructive to the veterinary community. I would never presume that I know more feline biochemistry than someone who has graduated from veterinary school. I don’t treat scores of animals every day or perform all manner of delicate surgeries and lifesaving procedures. My only real credential for writing this is that in 2000 I used diet alone to liberate my cat from the inflammatory bowel disease (IBD) that had plagued him for six very miserable years.

Despite a busy life, for several years I spent a substantial part of my time nearly every day helping to counsel distraught IBD cat caretakers on an online support group who had exhausted all the options offered by their veterinarians or who were alarmed by the side-effects from the multiple drugs their cats are taking. Another part of this site offers my experience and thoughts on the home-prepared diet that I and many others have used to cure (yes, cure) IBD, so I won’t go on about that here.

Among the key points I take away from the 1 December 2002 JAVMA article are the same principles I’ve learned from my own clumsy lay inquiries. Namely, that cats have: a strong need for high-quality protein (and lots of it); very specific amino acid requirements; a physiological decrease in ability to utilize carbohydrates from plant sources due to a lack of salivary amylase and a lack of specific enzymatic pathways that are present in other mammals; and short gastrointestinal tracts relative to omnivores. When I read all this – and then read a label on a bag of dry food whose first ingredients are grains (corn meal, etc.), meat “meals” and “byproducts” – I cannot reconcile the two. Of course, any food that isn’t the natural prey diet of mice and birds is going to be a compromise. But read the 1 December 2002 JAVMA article on feline nutrition–and then go and take a look at the primary ingredients in just two of the more commonly-advocated and veterinarian-prescribed foods for IBD cats:

  • Rice protein concentrate, brewers rice, hydrolyzed chicken liver, vegetable oil (preserved with BHA, propyl gallate and citric acid), hydrolyzed chicken, powdered cellulose, glyceryl monostearate, taurine, and ethoxyquin.
  • Poultry by-product meal, brewers rice, corn gluten meal, ground corn, animal fat (preserved with BHA, propyl gallate and citric acid), soy fiber, dried egg product, dried chicken.

How does anyone who reads the JAVMA article on nutritional lessons for carnivores justify serving “rice protein concentrate” to an animal that derives minimal nutritional benefit from plant-based carbohydrates? This is more than a “slight compromise” with the ideal. This is a backwards, upside-down diet. Are all these grains good for an obligate carnivore? I know that the pet food industry literature says that grains are generally “well tolerated” by cats. But if my cat is sick, I don’t want to give him food he might be able to ‘tolerate.’ I want optimal nutrition that’s going to build and sustain real health over the long haul. I want that even if my cat seems well.

The JAVMA article points out that cats eating dry food are chronically dehydrated when compared to cats eating canned food. The natural prey diet of a small cat has between 65 and 75 percent water. Dry kibble, with only about five to 10 percent moisture, draws even more precious moisture from a cat’s own reserves once it’s ingested.

Evidence that dry food contributes to numerous diseases that commonly plague the cat is mounting. In addition to IBD and obesity, among the all too common diseases associated with a steady diet of dry, carbohydrate-laden food are:

  • Feline Lower Urinary Tract Disease: Dry food is implicated as a risk factor for FLUTD. On the other hand, cats being fed a moisture-rich diet have an increase in urine volume and a decrease in urine specific gravity. This effectively dilutes the stone-forming minerals in the urine and therefore lessens the prevalence of stone formation and also ameliorates the effects of a 60-grit-like sandpaper sludge on the bladder wall which can lead to cystitis. According to notes published online following the 2003 AVMA convention, in the 1980s scientists linked a high incidence of struvite stones to high pH levels in food. And in the 1990s, scientists found that feeding acidifying diets to cats with struvite stones lead to an increased incidence of oxalate stones. Dr. Deborah Greco notes that “the ideal pH is 6.5,” which is the pH found in a mouse.
  • Diabetes: I am very intrigued by the work done by Elizabeth Hodgkins, DVM and others on how a high carbohydrate load in a carnivore’s diet wreaks havoc with blood sugar, leads to down-regulation of insulin-producing cells, and can lead to diabetes. She concluded that the classic prescription diets do not work because they are “loaded with carbohydrate that continues to dump sugar into the bloodstream of an animal that already has problems handling sugar.” Published notes following the July 2003 AVMA convention on Dr. Deborah Greco’s work reveal that, “cats are strict carnivores and, because of this, they have a tremendous ability to produce glucose from protein, but have difficulty processing carbohydrates. The feline liver has normal hexokinase activity, but no glucokinase activity. Thus, cats are limited in their ability to mop up excess glucose and store glycogen.” In his January 1994 article published by the UK’s Veterinary Times, veterinarian Graham Roberts notes that the use of high-fiber diets to reduce calorie intake contain “high levels of carbohydrates that can lead to glucose surges and increased insulin secretion.” A study whose results were announced in late 2004 demonstrated that feline patients at The Animal Medical Center in New York and Colorado State University of cats on a high-protein, low-carbohydrate diet, 68 percent went off insulin altogether.
  • Obesity: The handmaiden of diabetes, obesity, is reaching alarming proportions in cats. Despite ample scientific evidence (including a great deal cited by some renowned veterinarians) that dry food is where the most troublesome calories lie since carnivores convert carbohydrates into fat rather than energy, many veterinary reception walls are stacked high with bags of dry prescription foods.
  • Kidney failure: It’s disquieting to think about how chronic dehydration–a real risk with a dry diet–could be a contributing factor for chronic renal failure in cats.

I get discouraged that the pet food industry aggressively exploits the so-called “natural feeding craze.”Near as I can tell, this consists of putting essentially the same darn stuff in earth-tone colored bags, putting the word “nature” in the product name, making a colossal fuss about using Vitamin E as a preservative, and including soft-focus photographs of vegetables and whole grain rice on the package. Carrots and whole grain rice for carnivores? Hello? My brain starts coming out of my ears when I read the ingredient labels on many of these new “natural” foods. And don’t even get me started on the folly of the new “indoor formula” dry foods. Indoors or outdoors, cats are carnivores.

Please, Learn More About ALL Diets So You Can Help Us.

I appreciate that most vets currently feel on safer ground when they simply endorse the various formulations of pet foods that are sold in their offices. Believe me, I know that vets are busy people facing daunting economic pressures, time constraints, and lots of challenging and difficult clients. (Good grief, can you imagine what it would be like to have me as a client?) But isn’t it troubling that many vets are relying on the pet food industry rather than scientific principles and common sense when it comes to something as essential as what the carnivores under their care are eating every day? While there are certainly some laudable exceptions, my sense is that diet is often an afterthought when it comes to addressing many chronic feline health problems. At the risk of being shockingly presumptuous, I’ve included an easy-to-read sample client handout that could be used to introduce the basic principles of feline nutrition to keep in mind when selecting cat food. Since clients can be overwhelmed with all of the new information, my sense is that it is very important to provide something in writing that they can refer to later.

Dr. Graham Roberts puts it this way in his January 2004 article in the UK Veterinary Times:

Can we, as vets, continue to justify our selling of [commercial diets that cause problems in the first place] as ‘premium,’ ‘veterinary recommended,’ or ‘best quality’?”

The Food Allergy Misnomer.

Maybe the most confounding and, frankly, frustrating opinion I heard with respect to my cat is that his IBD disappearance (after switching to a balanced, raw diet) was a fluke and that he might have responded equally well to a commercial hypoallergenic diet. He most certainly didn’t. I tried so very many diets suggested by vets and none of them worked to relieve his chronic cramping, painful gas, daily diarrhea, and bloody stools. What cured him was a balanced, raw, grain-free diet consisting of meat, bone, organs, and a small handful of species-appropriate supplements to make up for what may be lost in the process of preparing and storing food. My long-suffering vet eventually acknowledged that I’d accomplished what he could not – a cure with diet alone. I didn’t just “manage” his malady or mask his symptoms with steroids. What worked was getting him completely off commercial food. And, I assure you that his story is not unique.

If my IBD cat was “allergic” to anything, it was to the glut of excess grains, byproducts, and questionable additives that are packed into virtually all commercial diets, especially kibble. I’m not saying that there aren’t cats with bona fide food allergies or cats that derive some minimal nutritional benefit from kibble. But in our case—and in the case of many people whom I have counseled as they try to safely troubleshoot diets for their very sick animals—calling bad digestive reactions to ingredients that shouldn’t be in a carnivore’s diet to begin with an “allergy” is a misnomer. If I become ill after eating ground glass shards, would my physician declare that I’m probably “allergic” to them? Or that I’d developed a hypersensitivity to glass shards? Of course not. My doctor would roll her eyes, instruct me to stop eating glass shards because they’re not what I’m physiologically designed to derive nutrition from, hopefully offer me some sound nutritional advice. And have a good giggle later with her colleagues about the nut job in his office. I hold open the possibility, however, that if I went to a veterinarian with the problem, I might very well be sold a pricey bag of “Prescription Formula Glass-Shard-Hypersensitivity-Diet.”

But seriously, sticking as close to Mother Nature as I can manage in my kitchen is what has made and kept him well. He was ill for six years, and in the decade following on that diet, he was one very healthy cat. No diarrhea, ever. He ate all kinds of meat with no problems whatsoever—rabbit, chicken, turkey, and guinea fowl, to be exact. He was not “allergic” to anything except to ingredients that no obligate carnivore should consume in the first place.

It is possible that another cat, maybe one who descended from a sturdier gene pool, would have been able to “tolerate” the grains and fillers in commercial foods. But IBD cats so often cannot. In my years of trying to help people with these animals, I’ve learned that they are the feline nutritional equivalent of the proverbial “canary in a coal mine.” They are the first to exhibit dietary sensitivity to ingredients that are inappropriate for their species. I concluded that I was putting my IBD cat at much greater risk by feeding species-inappropriate commercial foods than by feeding him a carefully-prepared, balanced, grainless, raw meat-based diet. This diet may not cure all cases, but shouldn’t it be considered as an option for any patient with refractory IBD?

Robust Nutritional Education Based on Unbiased Sources – Please.

People are hungry for sound, unbiased information from veterinarians on issues to help them make informed decisions about how and what to safely feed their cats. I’d love to see graduating veterinarians receive an accurate nutritional education for the species’ they will be treating. They could then offer sound and unbiased information to their clients. If that happened, I could stop writing these letters.

Instructors at veterinary universities today do their profession a disservice by looking the other way on these vital cat health issues, inviting the pet food industry to act as a proxy in something as central to health as nutrition. I appeal to you to consider what I’ve written and trust that I’m motivated solely by a desire to help sick animals and not to sneer at the mainstream veterinary community or the pet food industry. I hold out plenty of hope for you vets. You take an oath to protect animal health and your first obligation isn’t to shareholders.

We’ve lost our way when it comes to feeding cats. Let’s find our way back. Respectfully, the ball is in your court.

Thank you for taking the time to read this.

Share This Handout With Clients

Consider sharing or customizing this sample handout with clients. It’s designed to explain the core principles of feline nutritional requirements and help guide informed decisions about feeding cats.

by Aleksandra Urbanik 

by Ingrid Balzer 
by Isabelle ​Sekowski 
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