Omega Fatty Acids
My-Dog.info > Dogs, Diet & Food
The importance of essential fatty acids in canine and feline
nutrition has been known for some time. Their use as a dietary
supplement to improve the health and appearance of the skin and
hair coat has been well documented. By contrast, their use in the
management of skin disorders, particularly their
anti-inflammatory and anti-itch effects, continues to be the
subject of both ongoing research and lively debate.
Fatty acids consist of a series of carbon atoms that are
connected to each other by either a single or a double bond.
Fatty acids with two or more double bonds are termed
"polyunsaturated fatty acids" (PUFA). Polyunsatured
fatty acids include two important series of fatty acids called
the omega-3 series (n-3) and omega-6 series (n-6). Because
neither the omega-3 nor omega-6 series can be synthesized by dogs
and cats, they must be supplied in the diet and are termed
"essential" for this very reason. Common dietary
sources of omega-6 fatty acids include safflower, soy and corn.
Sources of omega-3 fatty acids include cold water marine fish and
mammals, as well as flax and soy.
Essential fatty acids (EFAs) have a number of important
functions in the body, especially in maintaining normal skin
structure and function. They make up a part of cell membranes,
and are also responsible for keeping the skin soft and pliable
and adding luster to the hair coat.
Linoleic acid (an omega-3 fatty acid) and linolenic acid (an
omega-6 fatty acid) are essential for both cat and dog, as well
as arachidonic acid (an omega 6 fatty acid) for the cat. Linoleic
acid is particularly important because it alone provides the
necessary conditions to facilitate moisturization of the skin.
The role of EFA's in the inflammatory process has been well
documented. The degree of inflammation appears to be determined
by the relative amounts of omega-3 and omega-6 fatty acids. Too
much omega-6 fatty acid may be promote inflammation while
relative increases in omega-3 results in less inflammation.
Dogs are able to synthesize all essential fatty acids from
dietary linoleic acid which is usually provided in canine diets.
While canned and moist diets usually have adequate levels of
linoleic acid, levels may fall below optimal requirements in
commercial dry foods because of rancidity due to improper or
prolonged storage or inadequate levels of antioxidants. To avoid
this, dry foods should be stored properly.
Cats require linoleic and arachidonic acids in their diet and
most commercial feline diets provide adequate levels to meet
their requirements. As is the case with canine dry diets, the
amount of linoleic acid may fall below adequate levels if
improperly handled.
The use of fatty acids as anti-itch and/or anti-inflammatory
agents, particularly for allergic disease and chronic itchiness,
has been studied extensively in both dogs and cats. Commercial
supplements may contain alpha-linolenic acid (sources: evening
primrose, borage seed, black currant oils) and/or
eicosapentaenoic acid (EPA) (sources: cold water marine fish
oil).
In itching caused by allergies, 20% of dogs and 50% of cats
may experience a decrease in itchiness with fatty acid
supplementation. Results may be dose dependent, with enhanced
efficacy noted in some cases when dosage levels were increased to
2-10 times the recommended dose. Duration of treatment may also
play a role, with some patients requiring up to 9-12 weeks of
therapy before a response is noted. Similarly, failure to respond
to one supplement does not preclude a favourable response to
another product.
Recent studies have shown a greater beneficial effect when
fatty acids supplementation is used in conjunction with other
treatments, such as antihistamine or steroid therapy. There is
also clinical evidence to suggest that decreased levels of
steroids are required to reduce itchiness if concurrent fatty
acid supplementation is administered.
Still controversial is the determination of the optimal levels
and correct ratios of omega-3 to omega-6 fatty acids in fatty
acid supplements. A recent study determined that a canine diet
containing an omega-6:omega-3 ratio of 5:1 to10:1 proved optimal
for the management of inflammation. Determining which fatty acid
supplement is ideal is made difficult because the levels of
omega-6 to omega-3 fatty acids in dogs and cats can vary widely
depending on the amount of fatty acids consumed in the diet.
Clinical response may be the only way of determining which fatty
acid supplement is most effective in clinical practice.
Reprinted with permission from www.animalhealthcare.ca
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