Vitamin E was first discovered
in 1922 when it was determined that female rats required vitamin E in order
to maintain a normal pregnancy. Vitamin E is a natural fat-soluble vitamin
and is stored in the liver. It is found in most tissues of the body. Vitamin
E is a potent antioxidant that neutralizes harmful molecules called "oxygen-free
radicals" that can damage cells. It has also been shown to have reduce inflammation,
enhance the immune system, and help cells fight infection.
The requirements for vitamin E in a diet depend on a number of factors, including
the dietary levels of polyunsaturated fatty acids and selenium, with which
it is closely linked.
In commercial pet foods, vitamin E is used to prevent the oxidation of fatty
acids which leads to rancidity. It accomplishes this by "neutralizing" the
free radicals which cause rancidity. However, during this process, vitamin
E is used up. Therefore, an increase in the amount of fatty acids in a diet,
especially unsaturated, requires a corresponding increase in the amount of
vitamin E and also increases an animal's requirement for vitamin E. For this
reason, feeding a diet that has been improperly prepared or stored, or supplemented
with large amounts of unsaturated fatty acids, can lead to a vitamin E deficiency.
The effects of vitamin E deficiency, while uncommon in dogs and cats, are
well-recognized. In dogs, vitamin E deficiency has been associated with impaired
immunological response, retinal atrophy, muscle dystrophy, testicular problems,
and failure of gestation. In cats fed marginal or low levels of vitamin E
and high amounts of unsaturated fatty acids, pansteatitis or "yellow fat
disease" can result.
Vitamin E supplementation has been shown to have some anti-inflammatory effect
on certain skin disorders in dogs. It is used in the treatment of certain
immune-mediated diseases, including such diseases as dermatomyositis, discoid
lupus erythematosus, pemphigus erythematosus, and epidermolysis bullosa,
with varying degress of success.
Vitamin E at high doses ( four to ten times the normal canine daily intake)
has been shown to be effective in the treatment of a disease called primary
acanthosis nigricans in dachshunds, with reductions in inflammation, crusting,
and itchiness. No toxic effects were reported. In fact, high levels of vitamin
E are considered to be non-toxic to animals, although an excess intake may
increase the requirements for vitamins A and D.
Studies have shown vitamin E to be ineffective on its own in the treatment
of itchiness and inflammation in dogs with allergic disease Decreased blood
levels of vitamin E were thought to cause suppression of the immune system
leading to demodicosis, a mite infestation in dogs that is the result of
a faulty immune system. Dogs with demodicosis were reported to show significant
improvement when treated with supplemental vitamin E . However, these findings
were contradicted by other studies which demonstrated no significant improvements
in dogs with demodicosis when supplemented with vitamin E.
Vitamin E plays a role in both canine and feline nutrition, both in preventing
certain deficiency-related disorders and as a form of adjunctive therapy
in certain skin diseases . It can also play an important role, along with
vitamin C, as an effective antioxidant in commercial pet foods.
Reprinted
with permission from Kristin Wood, Communications Officer
Canadian Veterinary Medical Association www.animalhealthcare.ca
The above information is simply informational. It's intent is not
to replace the advice of a veterinarian nor to assist you in making a diagnosis
of your pet. Please consult with your own veterinarian for confirmation of
any diagnosis. Your pets life may depend on it.
