Making homemade cat food may sound like exactly the kind of special care feline friends deserve, but according to a first of its kind study from researchers at UC Davis, such home-prepared diets may not be healthy or safe.

The study, released last week, examined the nutritional adequacy of 114 recipes found online and in recipe books. Researchers discovered that not only are many recipes lacking in essential nutrients, but 7 percent of the recipes examined included ingredients that are potentially toxic to adult cats, such as garlic, garlic powder, onions and leeks.

Most commonly, cats with medical issues such as diseases or that are picky eaters get put on home prepared diets so their owners can cater to their needs or preferences.

Homemade cat food diets also gained popularity when news broke more than a decade ago that toxic substances were found in commercial pet food imported from China. In addition, pet diets made with sustainable or organic ingredients have gotten attention as people become more interested in sustainable eating for themselves.

But lead study author Jennifer Larsen, a veterinary nutritionist with the UC Davis School of Veterinary Medicine, said it is “very, very rare that we find (a homemade recipe) that is balanced.”

“Cats require about 40 different essential nutrients,” Larsen said. “All of those things have to be present in appropriate amounts, and ratios are really important for pets.”

Yet only five of the 114 recipes were found to meet all but one of the essential nutrient requirements. Those five were authored by veterinarians, and while Larsen said they performed better than most in the study, they still had up to 12 nutrient deficiencies. Non-veterinarian recipes had up to 19 deficiencies.

One of the biggest issues was that recipes were too generic, Larsen said, which is contrary to the point of making customized cat meals.

“Generic recipes that are widely available are really too vague to be replicated and to be useful to owners,” Larsen said. For example, such recipes would instruct home chefs to “add a multivitamin appropriate for your pets,” she said, without defining what is “appropriate.”

Here’s how to ensure your cat is on an appropriate diet, according to Larsen:

  • If the cat has no medical difficulties that necessitate a special diet and the cat will eat anything, don’t bother with homemade cat food. “We generally recommend choosing diets from large, experienced manufacturers that have comprehensive quality control,” Larsen said. Pet food brands that have attempted to demonize mainstream commercial pet food have done so unnecessarily, Larsen said.
  • Cat owners who want to make homemade food should consult with a board certified veterinary nutritionist. These folks are actual pet doctors who can formulate home cooked diets based on an individual cat’s needs. Owners can start at their regular veterinarian for general recommendations, and the vet can then connect the owner with a board certified veterinary nutritionist for specific guidance.
  • The third option is a step down from a full consultation, but still a good option for people who want to home prepare. Pet owners can use online sources like balanceit.com, which is based in Sacramento, or petdiets.com to formulate diet plans. Both are run by board certified veterinary nutritionists, Larsen said, but because they are online programs, they still cannot get as specific and customized as a consultation.