Alternative Diets 101

By Dr. Caitlin Grant, BSc, DVM
Res. ECVCN (European College of Veterinary
and Comparative Nutrition)
DVSc Candidate

There are many reasons why a pet could be on an alternative diet — here, we'll provide information about the various alternative diet options that are available for both dogs and cats.  But before one can understand how a diet is classified as "alternative," we need to align on what a "conventional diet" is. A "conventional diet" is any diet that is:

• Commercially prepared
• Heat processed (cooked)
• Includes animal ingredients
• Contains all essential nutrients and meets a target nutrient profile

An "alternative diet" is therefore any diet that does not meet these requirements; there are a number of different categories which we'll describe. Alternative diets can still be commercially prepared, or they can be homemade diets.

A commercially prepared diet is one that has been manufactured by a pet food company and is purchased by the pet owner, usually at a store or through a website. A homemade diet is any diet that is prepared at home by the pet owner, using ingredients from a grocery store or butcher.

Alternative Diet Categories

Homemade cooked

• Ingredients purchased by pet owner and cooked before being fed to the pet.
• May or may not include following a recipe formulated specifically for the pet.

Things to keep in mind:

• Dogs and cats have requirements for essential vitamins and minerals — they won't get enough with human foods alone and therefore need to have a supplement included in their recipe.
• Veterinary nutritionists can formulate homemade diet recipes that are complete and balanced for the pet to ensure he or she is meeting all nutrient requirements.
• There are online resources where pet owners can purchase recipes, like balanceit.com.
• Each ingredient will have a very different nutrient profile, so when a recipe is being followed, ingredients should not be substituted for each other.

Homemade raw

• Ingredients purchased by pet owner and fed raw to the pet.
• May or may not include following a recipe that has been formulated for the pet.

Important considerations

• Same considerations as above for homemade cooked diets.
• Additional risk of bacterial contamination — several studies have shown an increased risk of contamination from harmful bacteria (e.g. salmonella, listeria, E. coli) in a raw diet.
• The risk of bacterial contamination resulting in a clinical problem is greater for pets (or humans!) who are young and growing or who have compromised immune systems.

Commercially prepared raw

• Fresh or frozen uncooked diet that is manufactured by a company and purchased by the pet owner.
• Often sold at pet specialty stores in the form of a meat patty.

Things to keep in mind:

• Important to check the label to determine if the diet contains all essential nutrients, or if additional supplementation is required.
• Same risk for bacterial contamination as above for homemade raw diets.

1. Commercially prepared freeze-dried raw

What is it?

• Low temperature dehydration (removal of moisture) of an uncooked diet that is manufactured by a company and purchased by the pet owner.

Things to keep in mind:

• The dehydration process does not effectively kill all harmful bacteria, thus there is still a risk of bacterial contamination.
• Some companies include an additional step to kill bacteria with high pressure processing (HPP).

Commercially prepared fresh food

• Pre-cooked and packaged prepared meals that are manufactured by a company and purchased by the pet owner, i.e. FreshPet and JustFood.
• Some companies have a subscription service and will deliver food straight to the pet owner’s door, i.e. The Farmer's Dog and Smalls for cats.

Things to keep in mind:

• Important to check the label to determine if the diet contains all essential nutrients, or if additional supplementation is required.
• Some companies will individualize a diet for a pet’s specific needs.
• Ask whether a veterinarian or a nutritionist is involved in developing the products.

Vegetarian & Plant-Based Diets

• Vegetarian diets lack meat (animal protein) ingredients but can still include animal products, such as dairy and eggs.
• Plant-based diets lack any animal derived ingredients and are made of only plant ingredients.
• These can be commercially prepared or homecooked, if a pet parent were to prepare meals using only plant ingredients. 

Things to keep in mind:

• Animals need nutrients, not ingredients — it's important to select ingredients that will provide a dog or cat with the nutrients they need.
• Cats are obligate carnivores and need animal protein in their diet to provide them with specific nutrients they cannot obtain from plant sources.
• Though an ingredient may have a good nutrient profile, it may not be as well absorbed by a dog or cat.

How common are these alternative diets?

In a 2008 survey in the USA and Australia, Laflamme et al. found:

• 90% of dogs and 99% of cats fed a conventional diet for at least half of their intake
• 3% of dogs and cats are fed exclusively a homemade diet
• 8% of dogs and 4% of cats fed a raw diet

And just 10 years later, Dodd et al. found in a survey of pet parents in the USA, Australia, and Canada that:

• 79% of dogs and 90% cats fed conventional diets for at least part of their intake
• 14% of dogs and 32% of cats fed conventional diets as their sole diet
• 7% of dogs and 4% of cats fed a homemade diet exclusively
• 10% of dogs and 6% of cats fed a raw diet exclusively

Why might a pet owner consider an alternative diet?

There are many reasons why a pet owner would consider an alternative diet over a conventional diet.  Some common reasons include:

• No conventional option that the pet will eat
• No conventional option that is appropriate for a pet’s medical conditions
• The feeling of more control over what the pet is eating
• Mistrust of pet food companies
• Feeling that an alternative diet is a healthier option

Need a vet?

Important considerations for all alternative diet options

• For any homemade diet, it is essential to include a vitamin and mineral supplement to ensure that the pet is meeting all of his or her nutrient requirements. A veterinary nutritionist can help by formulating a recipe that is individualized for your pet and can provide you with guidance on what supplements to choose.
• Young animals are more sensitive to nutrient deficiencies during the growth period, so it is strongly recommended to feed a conventional diet during this time period.
• Animals fed alternative diets should be assessed more frequently by a veterinarian to ensure the diet choice is still the best fit for that pet.

If you're considering an alternative diet for your pet, we recommend these next steps:

Homemade alternative diets:

• Talk to your veterinarian to help determine if you are feeding a complete and balanced diet.
• Ask your veterinarian for reliable resources if you want a homemade recipe formulated for your pet (i.e. a referral to a veterinary nutritionist).
• Consider cooking ingredients if you are feeding a raw food diet, especially for high-risk households.
• Let your veterinarian know if you are feeding raw food to your pet so they can take appropriate precautions such as isolating your pet from immunocompromised animals, advising you if your pet has a condition or is on medications that cause a compromised immune system, cleaning the exam room or equipment after in contact with your pet, and wearing gloves or other protective equipment if your veterinarian is more susceptible to infection.

Commercial alternative diets

• Look at the label to see if there is a nutritional adequacy statement indicating the product is complete and balanced for dogs or cats.
• Contact the company and ask whether there is a nutritionist involved in the product formulation.
• Talk to your veterinarian, let them know you are feeding an alternative diet or ask questions if you are considering switching to one of these diets.

References

Association of American Feed Control Officials. Official publication. Harrisburg, Pa: Association of American Feed Control Officials, 2019.

Dillitzer N, Becker N, Kienzle E. Intake of minerals, trace elements and vitamins in bone and raw food rations in adult dogs. British Journal of Nutrition. 2011; 106(S53–S56). 

Dodd SAS, Cave NJ, Adolphe JL, Shoveller AK, Verbrugghe A. Plant-based (vegan) diets for pets: A survey of pet owner attitudes and feeding practices. PLoS One. 2019;14(1).

Joffe DJ, Schlesinger DP. Preliminary assessment of the risk of Salmonella infection in dogs fed raw chicken diets. Can Vet J. 2002;43(6):441-442.

Laflamme DP, Abood SK, Fascetti AJ, et al. Timely Topics in Nutrition Pet feeding practices of dog and cat owners. J Am Vet Med Assoc. 2008;232(5):687-694.

National Research Council. Nutrient Requirements of Dogs and Cats.  National Academy of Sciences, 2006.

Stockman J, Fascetti A, Kass P, Larsen J. Evaluation of recipes of home-prepared maintenance diets for dogs. Journal of the American Veterinary Medical Association. 2013; 242(11):1500–1505. 

Strohmeyer RA, Morley PS, Hyatt DR, Dargatz DA, Scorza AV, Lappin MR. Evaluation of bacterial and protozoal contamination of commercially available raw meat diets for dogs. J Am Vet Med Assoc. 2006;228(4):537-542.

Weese JS, Rousseau J, Arroyo L. Bacteriological evaluation of commercial canine and feline raw diets. Can Vet J. 2005;46(6):513-516.