Commercial diets are frequently used due to their cost and convenience. The number of calories provided by commercial food varies depending on the region but can be very high in some countries (up to 90% in the USA). Some pet owners home cook for their pet. Thereare several reasons as to why. Some of those reasons1 include palatability (some dogs and cats do not find overall commercial diets appetent, even though there are hundreds of options in the market), mistrust of processing or ingredients, a wish to feed pet according to their own feeding habits/philosophy (vegan, organic, etc.), wish to include/exclude certain ingredients, or a wish to have a tighter control over what is being fed to their dog or cat. Finally, some owners choose home cooking because there are no commercial diets that are adequate, for example, when a pet has multiple diseases.
Independently of the reason, a homemade diet for a dog or a cat should be formulated in a way to ensure that all nutritional and energy needs are met.
How Are Homemade Diets Formulated?
The formulator needs to know
1. The nutritional and energy requirements of the species and life stage of the pet
2. Any maximum/safe upper limits set for specific nutrients for species and life stage
3. The nutritional and energy content of the foodstuffs chosen to formulate the diet
Nutrition and energy needs are compiled by the NRC2 (2006) from experimental data. Different associations (like AAFCO in the USA, or FEDIAF in Europe) base their recommendations for commercial diets on the NRC values.These are for healthy pets, and any modifications required for disease need to be checked in the existing literature. The NRC also reports safe upper limits for those nutrients that can have deleterious effects when fed in excess (such as vitamins A and D).
In order to meet these requirements and avoid toxic levels, the formulator will combine different ingredients (plus any required supplements). The nutrient and energy content of these ingredients is obtained from databases, usually public ones that each country maintains. These are usually less complete than pet food manufacturers’ internal database and do not contain ingredients that humans do not commonly eat. A home-cooked diet is as good as the database, and all have serious limitations.
Risks Associated with Homemade Diets
This is common when diets are formulated by lay people (not a veterinarian or a veterinary nutritionist) and if generic recipes are obtained from books or the internet. One study3 found that a vast majority of diets published in books and online for healthy dogs had nutritional inadequacies, plus almost no guidance on calorie intake. Similar results were observed in diets for pets with cancer4 and kidney disease5.
Other problems associated with “generic” online and book recipes include outdated strategies or nutritional requirements, over-complexity or simplicity, and use of dangerous ingredients (such as garlic). And they do not have the main benefit of homemade diets: customization to the pet.
Homemade diets properly formulated are prone to be changed over time6 (“diet drift”), and these changes can result in the diet becoming inadequate for long-term feeding or for the disease it was formulated for. The reasons owners give for these changes include lack of palatability, inability to obtain a specific ingredient, etc.
Even in properly formulated diets, database limitations include an element of risk. Homemade diets are not analyzed after preparation, and their formulation relies on theoretical values provided by the database. This means that the following assumptions are made: that the database reflects accurately the nutritional composition of the ingredients used; and that digestibility, bioavailability, and energy density of the ingredients is the same as in humans (most databases used for homemade diets are for people). Moreover, databases for human foodstuffs do not include concentration of some important nutrients for pets such as taurine and choline. Also, some ingredients are missing from the database, or we have incomplete entries. Moreover, the rarer the ingredient, the less reliable the database.
Finally, homemade diets, when properly done, are usually more expensive than commercial dry food, plus they require an important time and space investment.
Pros of Homemade Diets: When to Use Them
Homemade diets are a good option in several situations, as long as they are complete and balanced, and the patient has frequent veterinary visits. Homemade diets have the ability to be fully customized to patient and owner, and this is particularly useful when there are no commercial diets available for the patient.
Finicky Patients
Homemade diets might be better consumed by dogs and cats with capricious appetite, although this is not always the case. The owner must have realistic expectations, especially when the pet’s disease requires protein or fat moderation.
Concomitant Diseases
In some cases, the combination of diseases in one pet makes finding a commercial option difficult, although there are more and more “multifunction” diets in the market. Homemade diets, in these cases, allow provision of nutritional modifications without sacrificing important nutritional strategies for one or more conditions.
Electrolyte Alterations
One study7 reported the usefulness of low-potassium homemade diets in dogs with chronic kidney disease and hyperkalemia. Other electrolyte disturbances where homemade diets might help include idiopathic hypercalcemia in cats, although we do not have published data at this time.
High Digestibility
Homemade diets can be more digestible than commercial diets and this can be helpful in some gastrointestinal diseases (such as short bowel syndrome).
Ultra-low Fat Diets
Despite the presence of low-fat diets in the market, especially for dogs, there are some patients with fat-sensitive diseases that will require more aggressive fat restriction, such as some instances of hypertriglyceridemia, chronic pancreatitis, and lymphangiectasia. It is very important that these diets still provide enough essential fatty acids, thus, their formulation requires skill.
Resources
In order to obtain a homemade diet, it is recommended to contact a boarded veterinary nutrition specialist. In the US, the specialists are part of the American College of Veterinary Nutrition (www.acvn.org), whereas in Europe they are part of the European College of Veterinary and Comparative Nutrition (www.esvcn.eu/college/animal-owners). Other countries can have their own veterinary nutrition specialization organization, and the veterinary schools or the veterinary licensing bodies can also be contacted for information. Many services can work remotely through a referring veterinarian.
Patients eating homemade diets should be visited at least twice yearly (or even more, depending on the health status of the patient) to undergo a complete nutritional evaluation8 assessing the pet, the diet (in detail), and the environment, to ensure the homemade diet is being used properly and to assess if adjustments are needed. The WSAVA website has useful tools to perform this evaluation (www.wsava.org/Guidelines/Global-Nutrition-Guidelines).
References
1. Michel KE. Unconventional diets for dogs and cats. Vet Clin North Am Small Anim Pract. 2006;36:1269–81.
2. National Research Council (NRC). Nutrient requirements of dogs and cats. National Academies Press, Washington DC. 2006.
3. Stockman J, Fascetti AJ, Kass PH, Larsen JA. Evaluation of recipes of home-prepared maintenance diets for dogs. J Am Vet Med Assoc. 2013;242:1500–5.
4. Heinze CR, Gomez FC, Freeman LM. Assessment of commercial diets and recipes for home-prepared diets recommended for dogs with cancer. J Am Vet Med Assoc. 2012;241:1453–60.
5. Larsen JA, Parks EM, Heinze CR, Fascetti AJ. Evaluation of recipes for home-prepared diets for dogs and cats with chronic kidney disease. J Am Vet Med Assoc. 2012;240:532–8.
6. Johnson LN, Linder DE, Heinze CR, Kehs RL, Freeman LM. Evaluation of owner experiences and adherence to home-cooked diet recipes for dogs. J Small Anim Pract. 2016;57(1):23–7.
7. Segev G, Fascetti AJ, Weeth LP, Cowgill LD. Correction of hyperkalemia in dogs with chronic kidney disease consuming commercial renal therapeutic diets by a potassium-reduced home-prepared diet. J Vet Intern Med. 2010;24:546–50.
8. Freeman L, Becvarova I, Cave N, MacKay C, Nguyen P, Rama B, Takashima G, Tiffin R, van Beukelen P, Yathiraj S; WSAVA Nutritional Assessment Guidelines Task Force. WSAVA Nutritional Assessment Guidelines. Compend Contin Educ Vet. 2011;33(8):E1–9.