What vets need to know about 3 unconventional cat diets

A resident veterinary dietitian explores the associated risks and potential benefits of unconventional feeding practices

Unconventional diets and feeding practices for cats are becoming increasingly common. The results of a 2020 study show that while 90% of pet cats are offered a conventional commercial diet, only 32% of these cats receive exclusively a conventional diet. As the most common unconventional diet, raw foods were introduced to 53% of cats, and home-prepared foods were offered to 46% of cats.1

That’s why Martha G. Cline, DVM, DACVIM (Nutrition), has proven that veterinary professionals must understand the risks and benefits associated with unconventional diets. She examined the nutritional fitness of three popular diets and made clinical recommendations at her session presented at the 2022 Atlantic Coast Veterinary Conference in Atlantic City, New Jersey.2

1. Vegetarian and vegetarian diets

Cline began its review of vegan and vegetarian diets with reference to a study whose results showed that all commercially available vegan cat diets were deficient in at least one amino acid, and all were deficient in taurine.3 She added that this same study found that 13 of 24 dog diets and foods did not meet current label requirements of the American Feed Control Officers Association, casting doubt on the label’s accuracy.3

When examining what it would take to formulate a nutritionally appropriate vegetarian or vegan diet, Klein said, “So, is it possible to formulate a vegetarian or vegan diet for cats? Yes, you can definitely do that. Their eating may have another problem.” She later added, “…on the rare chance that you have a client who comes in who cares about this…I would like to inform them of this…emphasizing that They are obligate carnivores, [and] In fact, the literature does not support that we actually have quality products available even for these cats.”

2. Home made diets

Klein said the desire for home-prepared diets (HPD) can be driven by a customer’s feelings, such as avoiding additives and preservatives, enhancing the human-animal bond by cooking for their pet, or simply wanting to have complete control over their pet’s nutrition. A vet can also recommend HPD for comorbidities such as chronic kidney disease or inflammatory bowel disease.

“A home-made diet can provide complete, balanced nutrition when properly formulated and prepared,” Klein said. The problem, she said, is that customers have many resources available for HBD recipes (for example, online, books, and magazines) that vary widely in safety and nutritional adequacy. “It can be written by people who have absolutely no nutrition training,” Klein said. “My favorite is the great game breeder in Georgia who worked … as a secretary in a law firm, but in her spare time she wrote meals for Danish adults.”2 She also cited a study that examined 114 home prepared diets available online, all of which were nutrient deficient, including those written by vets.4

Klein recommended that general practitioners consult a board-certified veterinary dietitian when formulating diets for their clients. Follow-up consultations should assess adherence to the diet and check for nutritional imbalances.

3. Diets based on raw meat

Klein explained that raw meat-based diets (RMBDs), both commercial and home-prepared, can be nutritionally adequate when properly formulated. The danger in RMBDs, she said, comes from antibiotic resistance and the potential presence of zoonotic pathogens that lead to human and animal diseases.

Regarding antibiotic resistance, she referred to the CDC study of 14 commercially available raw food products in Europe, the results of which found that 100% of the samples carried enterococci that are resistant to erythromycin, streptomycin, chloramphenicol and tetracycline.5 “The really big concern, and the reason for doing this study, is that these researchers from the CDC have concluded that raw pet food could be a catalyst for emerging antibiotic resistance,” Klein said.

Another study analyzing 35 frozen RMBDs for cats and dogs found the following zoonotic pathogens, by percentage of infected products6:

  1. Escherichia coli Serotype O157:H7: 23%
  2. Broad spectrum beta-lactamase production coli bacteria: 80%
  3. Listeria monocytogenes 54%
  4. else Listeria Species: 43%
  5. salmonella Species: 20%
  6. Sarcocystis cruzi: 11% p
  7. S Tinella: 11%
  8. Toxoplasma: 6%

Klein advises that in addition to evaluating RMBDs for nutritional adequacy, they should also inform pet owners of these potential risks. Possible vectors of exposure to pathogens include food utensils, bowls, litter boxes, faeces, the diet itself, and cats with bacteria in their mouths or on their coats. The elderly, the young, pregnant and lactating women, and the immunocompromised are particularly at risk, she said.


  1. Dodd S, Cave N, Abood S, Shoveller AK, Adolphe J, Verbrugghe A. An observational study of pet feeding practices and how they changed between 2008 and 2018. veterinary rec. 2020; 186 (19): 643. doi: 10.1136/vr.105828
  2. Klein, M.; Unconventional diets … for cats! Filed At: Atlantic Coast Veterinary Conference; October 10-12, 2022: Atlantic City, New Jersey. www.dvm360.com/2022-acvc-proceedings
  3. Kanakubo K, Fascetti AJ, Larsen JA. Assessment of protein and amino acid concentrations and labeling of adequacy of commercial plant-based diets designed for dogs and cats. J Am Vet Med Assoc. 2015; 247 (4): 385-392. doi: 10.2460/javma.247.4.385
  4. Wilson SA, Villaverde C, Fassetti AJ, Larsen JA. Evaluation of the nutritional suitability of home maintenance diet recipes for cats. J Am Vet Med Assoc. 2019; 254 (10): 1172–1179. doi: 10.2460/javma.254.10.1172
  5. Freitas AR, Finisterra L, Tedim AP, et al. Linezolid and polydrug-resistant enterococci in raw commercial dog food, Europe, 2019-2020. Emerg infect dis. 2021; 27(8): 2221-2224. doi: 10.3201/eid2708.204933
  6. van Bree FPJ, Bokken GCAM, Mineur R et al. Bacteria and zoonotic parasites present in raw meat-based diets of cats and dogs. veterinary rec. 2018; 182 (2): 50. doi: 10.1136/vr.104535

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