Cat: Vitamins

Cost: approximately $46

Cats must have animal protein in their diets and, unlike dogs and humans, they don’t need to consume any carbohydrates at all, according to the Feline Nutrition Foundation. If they don’t get enough vitamins and minerals from their diets, they might need a vitamin supplement — particularly vitamin A, which cats can’t convert from plant-based beta-carotene like many animals can. Cat owners spend an average of $46 a year on vitamins, according to the APPA.