You Are What You Eat: Dog And Cat Nutrition Myths (Part 2)

Welcome back to this continuation of popular nutrition myths for dogs and cats (click here for Part 1). Let’s jump right in, and remember, PLEASE discuss all diet changes with your own veterinarian prior to making any changes.


I’ll admit, this one is quite catchy. “Byproducts†do not sound appetizing to me. Many pet owners today are drawn to the idea of feeding their pets “whole foodsâ€, and byproducts don’t sound like they fit in with that approach.

Let’s first take a minute to define what a byproduct is. The Association of American Feed Control Officials, or AAFCO (Association of American Feed Control Officials) is the premier organization setting standards for pet foods in the US. AAFCO guidelines define byproducts as a “secondary product produced in addition to the principal product.†It may NOT include digesta, teeth, hair, horn, hooves, or feces. Some examples of acceptable byproducts include liver, spleen, or other internal organs.

A few things to remember when thinking about byproducts:

  • Humans eat byproducts. Examples include haggus, tripe, and blood sausage. These may not be very common foods in our culture, but they are very common in many other parts of the world.
  • Byproducts are full of additional essential nutrients that are NOT found in animal muscle (this is what we often prefer to eat, such as steak, ground beef, chicken breast, etc). Byproducts can provide a rich natural source of amino acids and other nutrients that your pet needs to survive.
  • Many pet owners are already using animal byproducts as treats! If you’ve given your dog pig ears or bully sticks, you’ve fed them byproducts. And I’ll bet your dog loved it!


I’ve been a vegetarian for 27 years and counting. I understand the desire to carry the principles of reducing factory farming, animal abuse, etc, by pursuing a vegetarian or vegan diet for your pets. This can be a very difficult challenge for dogs; for cats, who are considered an obligate carnivore, this can prove dangerous or even fatal if not done properly.

Due to feline physiology, there are certain amino acids (protein building-blocks) that cats MUST get from animal sources. Whenever possible, it is highly recommended that cats maintain a carnivorous diet by eating a complete and balanced commercial diet that meets AAFCO standards.

If for some reason your cat requires a vegetarian or vegan diet, you should meet with your veterinarian in person BEFORE changing foods in order to discuss the nutritional needs of your individual pet. It is also strongly recommended that you consult with a qualified veterinary nutritionist to help you develop a nutritionally complete and balanced diet that reduces the risk of your pet developing a nutritional deficiency, which can prove fatal. Even then, your pet should be examined frequently by your veterinarian and have regular lab work performed, as pets who eat a non-traditional diet are considered high-risk animals.

This leads us to the next myth…


Most veterinary schools teach nutrition classes as part of the core curriculum, but even that isn’t enough to make us experts. All veterinarians are required to complete a specific number of hours of Continuing Education (CE) every year to ensure we are caught up with the latest-and-greatest in veterinary medicine, and many vets choose to spend some of those hours “beefing up†their nutrition knowledge on top of what was taught in vet school. As with any general practice doctor, we need to understand the basics of nutrition and metabolism to be able to serve our patients well on a daily basis.

But when we encounter a pet with a specific set of nutritional needs – for example, a cat with Inflammatory Bowel Disease and later-stage kidney disease – we may need to enlist the help of a Veterinary Nutritionist. This is a veterinarian who has completed extra training in Nutrition by completing a Residency. They are truly an expert in pet nutrition, and they are such a valuable resource for general practice veterinarians to rely on. If your veterinarian suggests consulting with a Veterinary Nutritionist, please thank them – your vet is trying to get the best possible care for your beloved dog or cat, and they are acknowledging the importance of nutrition in keeping your pet healthy and happy.


I’ll be the first to admit that veterinary hospitals need to make money. It’s true. They’re a for-profit business, and they need to generate revenue in order to pay their employees, stock the shelves with medications and supplies, pay the electric bill, etc. While veterinary diets do provide some revenue for veterinary hospitals, in truth they don’t generate very much – the mark-up on veterinary diets isn’t very high. The diets themselves are quite costly to design, research, and manufacture, so there isn’t much room for increasing the profit margins on these products.

Most veterinary hospitals carry prescription diets as a courtesy to their clients. When we diagnose a cat with kidney disease, or a dog with liver dysfunction, it’s much easier for the client to take home a bag of their pet’s new prescription diet to start that day, rather than searching for it at pet stores or waiting for it to be delivered from a website.

Whenever I recommend a diet to a client, I consider many factors including what’s best for the health of the animal, what fits within the client’s stated budget, ease of finding the diet, and whether or not I would consider it for my own pets. Most other veterinarians I’ve practiced with have the same approach. It’s important that you find a veterinarian you trust, so that you can feel comfortable with their dietary recommendations.

When feeding my own pets, I prefer Hill’s Pet Food and Royal Canin Pet Food. Their research-based approach to diet formulation sits well with me, and I feel comfortable with the quality of their foods.

MYTH #9 to 9000

It seems opinions about pet nutrition are in no short supply, and I could certainly extend this list to include many more myths circulating out there. I hope these articles will serve as a good jumping-off point to foster a collaborative discussion with your vet. Here are some reputable online resources to further your learning, but please remember to follow-up with your veterinarian as well:


ASPCA Cat Nutrition Tips

ASPCA Dog Nutrition Tips

OSU Guidance on Pet Foods