K. They are also important in the formation of certain hormones. Fats are similar to proteins in that they are made up of subunits called fatty acids. Just as there are different qualities of proteins, some fats are better than others in providing essential fatty acids. Fats can be found in both vegetable matter and animal tissue. Liquid fats like safflower and corn oils consist of 50-70 percent linoleic acid.
Arachidonic acid is found only in animal fats.
A cat's requirement for arachidonic acid in the diet makes it a truly carnivorous animal. Poultry fat is an excellent source of arachidonic acid. This is an expensive ingredient in pet foods, so most manufacturers use an alternative called beef tallow, which is less expensive but a relatively poor source of essential fatty acids. Even properly formulated, high-quality diets that have been stored for long periods of time or at high temperatures should not be fed to cats. Toxins present in rancid fats can accumulate in the cat's own subcutaneous fat stores along the back or in that udderlike fat pad that sways to and fro when they walk.