Skin Function Support FOD has an extraordinarily high content of omega 3 and 6 fatty acids from fish oil and Borage seed oil. This contributes to the condition of the skin and coat of cats with [aurl=73/]atopy[/aurl] (an allergy for certain substances in the environment, such as pollen or dust mites).. The food contains a high level of unsaturated fatty acids, vitamin A, E and B, zinc and selenium, which contribute to a healthy skin and beautiful coat.. The diet is very delicious; an easy way to provide your cat with additional fatty acids.. The food increases the acidity of your cat's urine. This contributes to the dissolution of struvite crystals that are already present. It also helps prevent the formation of new bladder crystals..