Holly Nash, DVM, MS - long article - click on source to read it all
Veterinary Services Department, Drs. Foster & Smith, Inc.
For many years, pet owners have given fatty acids to their dogs and cats to change a dull, dry coat into a more glossy one. More recently veterinarians have found that fatty acids play important roles in other areas of skin and coat health such as allergies, the control of inflammation, and the function of other body organs in dogs and cats.
What are fatty acids?
Fatty acids are specific types of polyunsaturated fats.
The two main classes of fatty acids we will be discussing are the omega-3's and the omega-6's. These classifications are based on molecular characteristics. (For you biochemistry buffs out there, check out the text box at the end of this article.) You may also have heard about omega-9 fatty acids. Omega-9's actually decrease the concentrations of omega-3 and omega-6 fatty acids in the blood and skin.
Which fatty acids do pets need?
Animals can produce some of the fatty acids they need, but not all of them. Those fatty acids which they can not produce themselves, but must be obtained through their diet, are called 'essential' fatty acids. Interestingly, what is 'essential' for one species of animal is not necessarily essential for another. For example, the fatty acid, arachidonic acid is essential for cats but not for dogs.
In some disease conditions, certain enzymes which convert one fatty acid to another may be deficient, or the animal may not be able to adequately absorb fatty acids from the intestine. In animals with these conditions, some of the 'nonessential' fatty acids actually become 'essential,' that is, required in the diet, and in higher amounts. Deficiencies of fatty acids may also occur with the use of fat-restricted diets in overweight dogs.
Fatty acids in foods are subject to degradation. Overcooking can destroy fatty acids. Improper storage or a suboptimal amount of antioxidants in dry food may result in rancidity and a subsequent deficiency in fatty acids.
Omega-3 fatty acids
Omega-3 fatty acids include:
ALA can be converted into EPA, however, this conversion does not occur in the skin. EPA is the workhorse of the omega-3 fatty acids and is incorporated into the cell membrane.
Omega-6 fatty acids
Omega-6 fatty acids include: