Over the last 50 y there have been numerous reports of
vitamin E deficiency in cats with the main cause of these
deficiencies being attributed to ingestion of diets high in
polyunsaturated fatty acids (PUFAs4
). Steatitis (“yellow fat
disease”) is attributed to vitamin E deficiency and has been
experimentally induced in kittens after feeding a commercial
cat food with a high fish content (1) and after feeding vitamin
E–deficient purified diet containing tuna oil and stripped
safflower seed oil (2,3).
Fish oil is a rich source of PUFAs, which are highly susceptible
to oxidation, and an increased intake of fish oil has
been associated with increased vitamin E requirements. Currently
the minimum dietary vitamin E requirement of cats has
been set at 30 IU/kg dry matter with dietary levels expected to
increase 3–4 times with a diet high in PUFAs (4). To prevent
vitamin E deficiency in cats fed commercially sold diets, the
Association of American Feed Control Officials (AAFCO)
recommends that fish oil–containing diets for cats should be
supplemented with 10 IU of vitamin E for every g of fish oil per
kg diet (5). However, there is no direct evidence to substantiate
the latter value or the increases recommended (4,5) in
adult cats.
The main objective of this study was to determine the
vitamin E requirements of adult cats fed high dietary levels of
PUFAs from fish oil.