Is Vet Recommended Food Making Your Pet Sick?

Cute Dog Isolated on white

Royal Canin, Science Diet, Eukanuba, and Iams are some of the most popular pet food brands recommended by vets. Yet these expensive and so-called “premium brands” often contain low quality and biologically-inappropriate ingredients that might be making your pet sick. Your pet’s health is too important (and vet bills are too high) to risk putting unhealthy food in your dog’s or cat’s bowl. Use this list as a tool to help you avoid the most unhealthy ingredients in pet food.

@mrsannief at Twenty20

Avoid dry food and pet food with too many carbs
First and foremost, ditch the dry food-vet recommended or not.
It’s probably in your pet’s bowl right now, huh? If it is, throw it out! Dry food was made for our convenience, not for our pet’s health.

Cats are obligate carnivores, which means meat is necessary for their survival. Wild dogs and cats mostly hunt birds and rodents, and that means their diet is very high in protein, fat, and water-not carbs. In fact, carbohydrates are not considered a necessary part of a dog’s or cat’s diet. The carbs most cats and dogs would consume in the wild consist of predigested grasses, fruits, and veggies found in their preys’ stomach.

Yet the average bag of dry food can be 30 – 70% carbs. You’ll often find foods like white potatoes, sweet potatoes, corn, tapioca, peas, and even fruits like blueberries in commercially manufactured pet foods (even the ones your vet recommends). All carbs break down into starch and then, ultimately, into sugar. If your pet eats too many carbs, they could become obese or diabetic (a growing problem for both cats and dogs). A recent study conducted by the Swedish University of Agricultural Sciences found “an increased risk of diabetes mellitus (Type 2) in normal-weight cats that consume dry food.”

As a holistic veterinarian and animal advocate with 22 years experience and thousands of hours of research under my belt, I’ve concluded that dry food is not a fit diet for our cats and dogs.

Jean Hove, DVM

Another problem with dry food is it’s dry. It lacks moisture. And while dry food may be convenient, consider this: a cat’s prey is about 70% water, and by contrast, dry food is only about 10% water. A cat’s thirst drive isn’t very strong (especially compared to a dog’s), and if your cat doesn’t drink enough water, they could become chronically dehydrated. This could lead to urinary tract disease, urinary crystals and stones, bladder infections, and renal (kidney) disease or failure.

We know that a cat’s sensitivity to thirst is blunted compared to a dog. They don’t voluntarily drink water like a dog would.” Cats have very concentrated urine and because they may not drink enough water, “we’re setting them up for urinary tract problems when their diet is low in liquids.” — Linda P. Case, M.S., author of The Cat: Its Behavior, Nutrition, and Health

Dry food is highly processed, contains too many carbs, and is exposed to high temperatures during the manufacturing process, which destroys nutrients. Dry food is the equivalent of feeding your pet fast food. It doesn’t belong in your pet’s bowl.

I have never seen a single case of serious obesity, diabetes, urinary tract disease, or IBD in a cat fed meat instead of commercial dry foods. — Elizabeth Hodgkins, DVM

So why do dogs and cats like dry food so much? It’s the flavor. Scientists working for the pet food industry have found just the right flavor combinations to spray over those pellets to make your pet gobble it up like “kitty crack.” 

Grains (another carb)
Grains are often used as cheap fillers in pet food, but they offer very little in terms of nutrition. Grains are not a natural part of your dog’s or cat’s diet, and eating them regularly could lead to digestive issues, food sensitivities, and/or allergies. Grains are high in carbohydrates and therefore not a species-appropriate food for your pet.

By-products are leftovers from the slaughterhouse (after they’ve sold everything they can for human consumption) and could include things like hooves, heads, and lungs. Meat by-products are an inexpensive way for manufacturers to keep the protein levels high in pet food. The downside is that the quality of the protein is low.

Meat meal
Meat and bone meal
Meat by-product meal
Animal by-product meal
When the protein source is not specifically named (e.g., chicken, turkey, beef), it’s unclear what the meat is and where it came from. It could be road kill, dead zoo animals, or diseased, or heavily-medicated livestock. Any form of a meat “meal” generally means that the manufacturer uses low quality ingredients. So don’t pay a high price for this mystery meat.

Large fish, like tuna
Large fish often contain industrial chemicals like PCBs (polychlorinated biphenyls), pesticides, and/or insecticides (like DDT) and have high mercury levels. Mercury can affect the nervous, digestive, and immune systems, as well as the lungs and kidneys. If you want to avoid fish contaminated with mercury, stay away from big fish, like mackerel, marlin, and tuna, in your pet’s food. Read ingredient labels carefully because what it says on the front of the label may not correspond with what’s inside.

Ethoxyquin in fish meal
Ethoxyquin is an artificial preservative often added to the fat or oil in a pet food containing fish meal. It’s added to help prevent the food from spoiling. But over time, the preservative can cause liver, kidney, and potentially lung, including asthma. Ethoxyquin is prohibited in the European Union and Australia. The U.S. does not allow its use in human food products (except for a few spices) because it’s considered a carcinogenic. It’s also important to note that Ethoxyquin won’t necessarily be listed on the label, as it’s often added to meat before arriving at the pet food manufacturer. If you want to avoid ethoxyquin, skip pet food that contains fish meal.

Paul B on Flickr@CC

Soy & corn
Avoid soy and corn in your pet’s food, especially if your dog or cat has allergies or digestive issues. Soy and corn are generally used as inexpensive substitutes for high quality and species-appropriate ingredients. Soy can be listed as soy meal, soy flour, soy protein, grits, hulls, vegetable broth, textured vegetable protein, or TVP (textured vegetable protein). Both soy and corn are likely GMOs (genetically modified organisms) and could contain chemical residue from the pesticides or herbicides sprayed on the crops at the farm.

Carrageenan is a common food additive in pet food. It’s used as a thickener, emulsifier, and/or stabilizer. Carrageenan has been shown to cause gastrointestinal inflammation. Chronic inflammation can lead to health issues, so avoid carrageenan if your pet has any health conditions or a sensitive stomach.

BHT (butylated hydroxytoluene) potentially causes cancerous tumors.
BHA (butylated hydroxyanisole) is a likely human carcinogen.
TBHQ (tertiary butylhydroquinone) has been shown to produce pre-cancerous stomach tumors in lab animals.

BPA (Bisphenol A)
BPA is an industrial chemical found in plastic and often in the lining of canned food, including pet food. Research shows that BPA affects the brain, behavior, and prostate gland of fetuses, infants, and children. While no research has been done on the how BPA affects pets, it’s best to avoid it.

OutOfwave on Flickr @CC

Natural flavor/fish flavor
Natural flavor generally isn’t natural, but rather enhanced in a lab. Opt for real food instead of food “flavors.”

Animal protein in the top three ingredient spots
The ingredients listed on a pet food label appear in order based on their precooked or raw weight, but when protein is added to the pet food, it is cooked. Chicken may be listed in the #1 spot on the ingredient label, but after it’s cooked it loses moisture and therefore weight. So in reality, the chicken may no longer be the dominant ingredient in the food. One way to find a high quality pet food is to look for a named animal protein (chicken, turkey, beef) in the top three spots on the ingredient label.

Ingredient Splitting
This is one to watch out for closely. Pet food manufacturers know that savvy consumers want a high quality protein in the #1 spot on an ingredient label. So if a manufacturer’s product has more corn than meat protein, they may try to hide that fact by splitting the corn into different categories, like corn meal and corn flour.

For example, let’s say that 18% of a can of pet food is turkey and 30% is corn. Because corn is a higher percentage than turkey, the pet food manufacturer would have to list it in the #1 spot on the ingredient label. But if they split the corn into 15% corn flour and 15% corn meal, turkey now goes in the number #1 spot at 18%. There’s actually more corn than turkey in the pet food, but the average consumer wouldn’t notice. Sneaky, right?

One way to avoid being tricked by ingredient splitting in your pet’s food is to look for a high quality meat protein in the top three spots on the label and avoid foods that have too many carbs.

Other things to look for
Is the pet food human grade? If so, this means your pet is eating a high quality food fit for human consumption.

Does the food have vitamins and minerals? They are an important part of a balanced diet.

Is the pet food AAFCO (Association of American Feed Control Officials) approved? AAFCO regulates the sale and distribution of animal feed.

Is the food USDA certified organic? If so, that means the food is free of pesticides, antibiotics, hormones, and GMOs (genetically modified organisms).

When you read an ingredient label, it never hurts to ask yourself, “Would my pet eat this in the wild?”

Jeremy Weber on Flickr @CC

Now that we know what ingredients to avoid in pet food, let’s see how a can of Hills Science Diet, a vet recommended brand, rates.

SD_K9_C_sen_NA_o_O_n_chkn_200_en Hills Science Diet
Adult 7+ Chicken & Barley Entrée


Water, Chicken, Cracked Pearled Barley, Whole Grain Corn, Pork Liver, Dried Whey, Dried Beet Pulp, Soybean Oil, Corn Gluten Meal, Chicken Liver Flavor, Choline Chloride, Fish Meal

Calcium Carbonate, vitamins (Vitamin E Supplement, Thiamine Mononitrate, Ascorbic Acid (source of Vitamin C), Niacin Supplement, Calcium Pantothenate, Vitamin B12 Supplement, Pyridoxine Hydrochloride, Biotin, Riboflavin Supplement, Vitamin D3 Supplement, Folic Acid), Iodized Salt, Potassium Chloride, Iron Oxide color, minerals (Zinc Oxide, Ferrous Sulfate, Manganese Sulfate, Copper Sulfate, Calcium Iodate), Taurine, L-Tryptophan, Beta-Carotene.

The first ingredient is water. This means that there’s more water in this food than anything else. Ideally, it should be a high quality animal protein.

The second ingredient is chicken, which is a good animal protein. But once the chicken is cooked, it could weigh less than the third ingredient, which is cracked pearled barley, and possibly also less than the fourth ingredient, which is whole grain corn.

It appears this company may have “split” corn into “whole grain corn” and “corn gluten meal” so savvy consumers won’t detect how much corn is actually in this food.

When put together, water, corn, and barley make up the bulk of this food, not high quality animal protein. As a result, this food is very high in carbs.

Pork liver may not be what you expect when you buy a “chicken and barley entrée.”

Whey is derived from dairy. Not all animals tolerate dairy well.

Dried beet pulp is an inexpensive filler. It can provide fiber.

Soybean oil is likely a GMO and may contain potentially cancer-causing herbicide or pesticide residue. Soy is an inexpensive protein source, but not a biologically-appropriate one.

Corn gluten meal is not a healthy meat-based protein; it’s an inexpensive plant-based substitute. It’s also likely a GMO with pesticide residue.

This pet food contains “chicken liver flavor” rather than actual chicken liver.

Fish meal is an inexpensive and less nutritious substitute for fish and may contain the artificial preservative ethoxyquin. Would you expect to find fishmeal in a chicken and barley entrée?

The manufacturer doesn’t indicate what kind of fish is used, so we have no way of knowing if it’s tuna, which is high in mercury.

Most of the protein in this expensive vet-recommended food is from corn and grains. It’s too high in carbs, which is not a biologically-appropriate food for cats or dogs. The food contains inexpensive, low quality ingredients like chicken liver flavor and fish meal. Probably not what you’d expect from one of those so-called premium pet food brands. If you’re going to spend more money on pet food, choose a brand that contains higher quality ingredients.

Jeremy Weber on Flickr @CC

DISSECTING A LABEL: EXAMPLE 2 Rabbit-and-Lamb-Moist-Daily-Dog-Cuisine
ZiwiPeak, Moist Dog Food
Rabbit & Lamb


Rabbit Meat, Lamb Meat, Lamb Liver, Lamb Lung, Lamb Tripe, Lamb Heart and Kidney, New Zealand Green-Lipped Mussel

Lecithin, Dried Kelp, Agar-Agar

Taurine, Choline Chloride, Niacin Supplement, Vitamin E Supplement, Calcium Pantothenate, Thiamine Mononitrate, Riboflavin Supplement, Pyridoxine Hydrochloride, Vitamin A Supplement, Biotin, Vitamin B12 Supplement, Folic Acid,  Vitamin D3 Supplement   Minerals – Potassium Chloride, Tetrasodium Pyrophosphate, Calcium Carbonate, Iron Proteinate, Zinc Proteinate, Sodium Selenite, Manganese Proteinate, Copper Proteinate, Calcium Iodate

The label says the food contains rabbit and lamb and rabbit and lamb meat are the #1, #2 and #3 ingredients.

New Zealand Green-Lipped Mussels are added for their anti-inflammatory properties. They naturally contain a variety of vitamins, minerals, amino acids, Omega-3 fats, antioxidants, and enzymes.

Dried kelp is high in minerals, vitamins, amino acids, and trace elements.

Lecithin is made of phosphoric acid, choline, fatty acids, glycerol, glycolipids and triglycerids. It’s used as a natural emulsifier in foods.

Agar-Agar is derived from red seaweed and is used as a thickening agent in food.

Taurine is an essential amino acid.

Vitamins and minerals are a necessary part of your pet’s healthy diet.

ZiwiPeak is high in protein, made with high quality ingredients, and the label depicts what’s actually in the food. Between this and the Hills Science Diet Chicken & Barley Entree, which food would you rather give your dog?

Bob Travis on Flickr @CC

Additional things to keep in mind

Rotate your pet’s food
No pet food is perfect, and if your dog or cat is eating the same food day after day, the imperfections in the food could have an impact on your pet’s health over time. Switch up the animal protein (turkey, chicken, beef) and find one or two brands your pet likes and rotate them daily, weekly, or monthly.

Special diets
The brands your vet recommends often make special foods for various health issues and stages of life. But read the ingredient label carefully and ask yourself, “Is there really anything in this food that provides extra benefits for my pet? Or is this just marketing?” If there is something your pet needs (often it’s more or less protein), you can generally find that in a healthier brand.

It may cost a little more, but it’s worth it
Good health starts with highly nutritious and biologically appropriate food. Unfortunately, that’s not often found in the bags and cans of food sold at your vet’s office. Many experts believe a raw diet more naturally reflects what your pet would eat in the wild, but if that’s not an option for your pet, choose a canned food with the highest quality ingredients you can find. And rather than buying food from your vet’s office, find a healthy pet food store in your area or do some investigating and order what you want online. Spending the extra money on high quality pet food now, will help keep your pet healthy and could save you hundreds or even thousands on expensive vet bills later. And that’s something every pet owner can feel good about.

Learn More
Little Big Cat – “10 Reasons Why Dry Food Is Bad for Cats & Dogs”
Feline Nutrition Foundation – “Bio-Inappropriate: The Dangers of Dry Food”
Popular Science – “The Chemistry of Kibble, The Billion-Dollar, Cutting-Edge Science Of Convincing Dogs and Cats Tp Eat What’s In Front Of Them.”
Cornell University College of Veterinary Medicine – “Feline Obesity”
Dogs Naturally – “Dog Food: Ten Scary Truths”
Only Natural Pet – “Top 10 Myths About Pet Food and Nutrition”
Healthy Pets with Dr. Becker – “From Best to Worst –My New Rankings of 13 pet foods”
CapCod.com – “Don’t Fall for the ‘Grain-Free’ Trick Pulled by Some Pet Food Makers”
Professor’s House – “Dry Cat Food – Is Kibble Safe for Cats?”
Healthy Pets with Dr. Karen Becker – “Largest Study EVER confirms what cats really want to eat”
Little Big Cat – “10 Reasons Why Dry Food Is Bad for Cats & Dogs”
Dog Food Advisor – “The truth about animal by-products”
Natural Resources Defense Council (NRDC) – “Consumer Guide to Mercury in Fish”
Dog Food Advisor – “These dog food preservatives could be toxic to your pet”
Healthy Pets, Dr. Karen Becker – “The Very Food Your Pet is Addicted to May Contain Deadly Ethoxyquin”
Taylor Francis Online – “Effect of butylated hydroxytoluene and other antioxidants on mouse lung metabolism
Toxicological Sciences – “Sequential Study of the Chronic Nephrotoxicity Induced by Dietary Adminstration of Ethoxyquin in Fischer 344Rats”
Dr. Jean Dodds’ Pet health Resource Blog – “The Skinny on Soy: Exposing a Popular Pet Food Protein”
Healthy Pets, by Dr. Karen Becker – “Here’s One Protein Dog and Cat Owners Should Steer Clear Of”
Dr. Jean Dodd’s Pet Health Resource Blog – “The Skinny on Soy: Exposing a Popular Pet Food Protein”
Dog Food Advisor – “Gluten – Beware this Inferior Dog Food Protein Impostor”
Primal Pooch – “The Great Debate: Do Dogs Need Fruits and Vegetables?”
Dog Food Advisor – “Are dogs carnivores or omnivores?”
The Cornucopia Institute – “Carrageenan”
Little Big Cat – “Carrageenan: a Controversial Pet Food Additive”
Environmental Working Group – “Bisphenol A – Toxic Plastics Chemical in Canned Food”
Environmental Working Group – “Synthetic Ingredients in Natural Flavors and Natural Flavors in Artificial Flavors”
Dog Food Advisor – “Ingredient Splitting – The Dog Food Industry’s Dirty Little Secret”
Ped Med Us National Library of Medicine National Institutes of Health – “Gastroprotective and anti-inflammatory properties of green lipped mussels (Perna canaliculus) preparation.”
Chris Kresser – “Harmful or Harmless: Guar Gum, Locust Bean Gum, and More”

Feature image by KPGS at iStock