Influence of number of ingredients, use of supplement and vegetarian or vegan preparation on the composition of homemade diets for dogs and cats

Background Homemade diets are a worldwide trend, and many recipes are currently available on websites but may not be considered balanced. This study aimed to evaluate if the number of ingredients, supplement, or vegetarian/vegan-only ingredients included in a recipe influence the nutrient content of homemade diets for dogs and cats. Chemical analyses were performed on 75 diets for dogs and 25 for cats prepared according to websites' recipes, and minerals were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). Results Canine diets that met fat requirements had more ingredients than those below recommendations. None of the cat diets met iron requirements, and feline diets that met requirements of manganese had fewer ingredients and those that supplied requirements of protein and sodium had more ingredients than the diets below recommendations (p < 0.05). Non-supplemented canine and feline diets had calcium and calcium:phosphorus ratio below recommendations (p < 0.05). Non-supplemented feline diets had lower sodium and iron, and zinc levels were below recommendation in diets for both species. Diets with animal products for dogs had higher levels of protein and zinc, although zinc was deficient in both groups, and there were higher amounts of crude fiber, magnesium, and manganese in vegetarian/vegan diets (p < 0.05). Diets with animal products for cats had higher levels of protein (p = 0.003), but there was a higher amount of crude fiber (p = 0.014) in vegetarian/vegan diets. Conclusion The number of ingredients and vegetarian/vegan preparation did not guarantee nutritional adequacy of diets, and the presence of supplement did not ensure a balanced diet.