Essential fatty acids (EFAs) are "good" fats which are required for normal growth and physiological integrity. They are important for your pet to maintain a healthy skin and coat, and promote strong immune, cardiovascular and nervous systems. Because essential fatty acids are not made in the body, they need to be ingested. This is easily done for your pets by providing them as food or supplements. The best source for EFAs is seafood. While some plants (such as flax seed) do contain EFAs, they do not contain the important long chain fatty acids EPA and DHA which can only be found from marine sources. The amounts average in the following range: EPA 365-410, DHA 410-455.