Accessibility to pet food has not always been a short drive or click away. Before commercialization, dogs were left with whatever food families could spare from their dinner tables—including bones, bread, cabbage, and potatoes. It was not until the Industrial Revolution that the rising middle class took an interest in converting dogs from working animals to domesticated companions. The first commercially prepared food was documented around 1860, when a businessman in England created a dog biscuit composed of wheat meal, vegetables, beetroot, and beef blood. This inspired additional companies to formulate their own recipes, and thus launched an industry projected to reach $136.82 billion by 2028.
Presently, finding the “best” food for your pet has never been more difficult. Pet food companies are stocking shelves with shiny, bright-colored packages and showcasing taglines that promise they will cater to your dog’s individual needs. The harder the answer is to find, the more it becomes apparent that pet owners will continually search for, and pay for, what they feel is best for their pet.
Luckily, among the chaos that is the pet food industry there stands a sovereign body that exists to provide a framework for animal dietary nutrition—the Association of American Feed Control Officials (AAFCO). This private non-profit corporation establishes practical nutrient profiles for dog (and cat) food and provides nutritional adequacy statements that can be placed on the outside of pet food packaging to let consumers know whether a diet provides complete and balanced nutrition for the animal and labeled life stage.
While these guidelines are helpful, it is important to note that AAFCO does not regulate pet food. This means that companies can place an AAFCO statement on the back of their package without undergoing feeding trials to substantiate these claims. In addition, meeting the recommended requirements does not provide any information on the quality of the ingredients. It is paramount to find a trusted manufacturer with nutritional expertise.
While a number of grain-free diets and raw diets may have AAFCO statements located on the back of their packaging, they are not recommended by the American Veterinary Medical Association (AVMA), for reasons I will discuss.
A grain-free diet is considered one that contains a high percentage of peas, lentils, other legume seeds, and potatoes, as ingredients that are listed within the first ten items listed on the packaging label. Grain-free diets have recently been linked to the development of a heart disease in dogs known as dilated cardiomyopathy.
Dilated cardiomyopathy (DCM) is a disease of cardiac muscle that causes heart chamber enlargement, thereby compromising the pumping ability of the heart. As the heart becomes more and more dilated, the heart valves leak and cause a build-up of fluid in the chest—a disease known as congestive heart failure (CHF). While dogs may not show any clinical signs of DCM early in the disease process, progression can lead to weakness or tiredness associated with exercise, a heart murmur, an arrythmia, collapse, and eventually difficulty breathing due to CHF. While there is an established genetic link to the formation of DCM, more recent research now also presents a nutritional component.
So how are grain-free diets potentially linked to the formation of dilated cardiomyopathy in dogs? Research performed by veterinary cardiologists Dr. Joshua Stern and Dr. Joanna Kaplan at the UC Davis School of Veterinary Medicine (shoutout: Go Aggies!) delved into the dietary association between diet and the development of heart disease, which eventually led to an FDA-published warning and further investigation.
The research study involved 24 golden retrievers diagnosed with dilated cardiomyopathy and documented taurine deficiency. Taurine is an important amino acid for cardiovascular function. Twenty-three of the twenty-four dogs in the study were being fed grain-free, and/or legume-rich diets—both of which were presumed taurine-deficient. When the cardiologists prescribed a diet change and taurine supplementation, the results showed all but one of the twenty-four dogs improved in cardiac functional parameters, even those with DCM severe enough to cause congestive heart failure.
As a result, the FDA released its own public alert on reported data that included various other dog breeds, many without known genetic predisposition to DCM. While large and giant breed dogs are more typically associated with DCM, small and medium breed dogs such as Shih Tzus, whippets, and bulldogs, among others, were included in the FDA reported cases of nutritionally mediated DCM. These dogs were fed grain-free diets anywhere from a few months to years. This data presents canine DCM as a multifaceted condition with contributing factors that include genetics, underlying medical conditions, and, of course, diet.
If you are feeding your dog a grain-free diet, discuss it with your veterinarian who may choose to perform diagnostic testing and can aid you in choosing a new diet appropriate for your pet. Do not abruptly change your pet’s diet or supplement taurine without a discussion with your veterinarian.
Raw diets are another category of pet nutrition made popular by mainstream media misconceptions. Feeding a raw diet involves primarily uncooked meat, bones, and organs that are either home-made or commercial diet formulations. Those who feed their dogs raw diets have more than likely heard and perhaps prescribed to the rationale, “dogs descend from wolves,” and thus should eat similar diets. While I would challenge anyone to find a Shih Tzu in the wild fervently hunting for its next meal, the more important point is recognizing the divergence of dogs from their wolf ancestor occurred over 100,000 years ago. Over this time, anatomical changes—skeletal structure, dentition, and gastrointestinal tracts—occurred, posing different physiologic nutrient requirements for dogs than those of their ancestors.
Nutritional imbalances are common when feeding raw diets—excesses and deficiencies are found of calcium, phosphorous, copper, zinc, iodine, vitamin A, and vitamin D. Imbalances can lead to malnutrition and systemic clinical signs. In addition, raw diets can cause parasitic, bacterial, and/or viral infection. Compounding the concern is the ability for these infections to also be zoonotic—meaning humans can become infected as a result of feeding and/or preparing raw food for our dogs.
The FDA conducted a study that took 196 raw canine and feline food samples from a variety of manufacturers and screened them for contaminants that can lead to food-borne illness. Of the 196 samples, 15 were positive for Salmonella and 32 were positive for Listeria monocytogenes. This presents not only a concern for pet health but also a public health risk, because human owners are handling these products. The American Veterinary Medical Association official policy discourages feeding raw food to dogs or cats due to infection risks of animals and people, especially for immunocompromised individuals.
Choosing a Diet
When picking out a new diet for your four-legged bestie, be conscientious in your examination of pet food labels. The World Small Animal Veterinary Association (WSAVA) Global Nutrition Committee provides useful guidelines on selecting pet food: (1) Does the brand employ a veterinary nutritionist? (2) What is the quality control process for ingredients and finished products? (3) Who formulates the diet? (4) What kind of product research or nutrition studies have been conducted, and are they published in peer-reviewed journals? In addition, consult veterinary guides on what to look for within the nutrition label.
Use the additional resources and information provided in this article to help you make a thoughtful and informed decision about your pet’s nutrition.
Peyton B. Aaronson, DVM is a veterinarian at VCA Desert Animal Hospital located at 4299 Ramon Rd, Palm Springs, CA 92264. Dr. Aaronson is a graduate of UC Davis School of Veterinary Medicine, Class of 2021, and UCLA, Class of 2016. vcahospitals.com/desert (760) 778-9999