While most dog foods contain protein from meat sources, you can switch your dog to a vegetarian diet if it contains sufficient amounts of other types of protein. As omnivores, dogs can live on a meatless diet made up of vegetables, eggs, beans and dairy products like cheese. With a slow transition to his new food, your dog can acclimate to his new diet with little gastrointestinal distress. Monitor your dog through this process and during the initial transition to see that he tolerates his new food well and does not have any food allergies to the vegetarian diet.
Speak with your veterinarian about the ingredients in the food you plan to feed to your dog. Ask her what the amounts of nutrients, not provided by vegetarian sources, are needed to supplement your dog's diet. Homemade vegetarian foods will require specific supplementation with vitamins, amino acids and minerals.
If your dog suffers from a chronic, debilitating condition such as kidney disease or diabetes, ask your veterinarian if a meatless, lower-protein diet is appropriate for him.
Purchase ready-made vegetarian dog food, which usually requires no supplementation, or make the food yourself. Choose a commercially made vegetarian diet that has been approved by the Association of American Feed Control Officials to ensure it is nutritionally complete for your dog, recommends the American Society for the Prevention of Cruelty to Animals. AAFCO conducts food trials to ensure that a dog food contains all of the necessary ingredients to sustain a healthy dog.
If making the food, add pre-made vegetarian dog food supplements, typically found in pet supply stores or through an Internet retailer. Ask the retailer if these supplements have been approved by a veterinarian or AAFCO.
Slowly introduce the new food to your dog over the period of two weeks to a month. This will lessen any stomach upset in reaction to the new food. Feed your dog 1/4 of a portion of the new food mixed in with 3/4 of a portion of his existing food. Increase the amount of new food, and decrease the amount of old food, by 1/4 of a portion every three to five days, depending on how your dog reacts to the new food.
Transitioning to a canned variety of vegetarian food may take less time than switching to a dry version because canned food smells more appetizing to a dog.
If, at any point, your dog has loose stool or stomach upset, slow the process down and allow for a few extra days for each transition.
Tempt your dog to try the new food, especially in larger amounts, by sprinkling grated cheese or chopped, hard-boiled eggs on top. These vegetarian ingredients provide extra protein for your dog and will encourage him to try the new food.
Take your dog to a veterinarian to have a complete blood panel performed after one or two months on his new diet. This test will evaluate whether your dog is getting the nutrients he needs from his new food. The doctor will also physically examine your dog to evaluate his weight and coat for any signs of distress due to the new diet. Continue to monitor your dog's health with a veterinarian every six months.