Cats need several different kinds of nutrients to survive: amino acids from proteins, fatty acids, carbohydrates, vitamins, minerals, and water. Sometimes an animal needs high energy nutrition in a hurry, as do underweight animals suffering from conditions resulting from malnutrition, parasite infestation or debilitating disease. Nutri-Cal is a tasty, high calorie dietary supplement in a paste form for dogs and cats. It is intended for animals that require extra calories and vitamins in the diet.