In fact, the best commercial pet food companies work closely with veterinarians and veterinary nutritionists to formulate diets for very specific medical conditions. A therapeutic diet does little good if the cat refuses to eat it. Another category of therapeutic diets I prescribe frequently are hydrolyzed diets for patients with suspected food allergies or sensitivities. That said, fresh food diets can be an excellent option for some animals. This applies to fresh food diets as well prescription diets.