To determine how long serum concentrations of omega-3 fatty acids remain elevated after cessation of dietary fish oil supplementation.
12 healthy Beagles.
Baseline serum concentrations of linoleic acid, linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were measured. Dogs were then fed a diet supplemented with soybean oil or fish oil for 8 weeks, and serum fatty acid concentrations were measured while dogs were fed the experimental diets and for 18 weeks after they were switched to a maintenance diet.
For dogs fed the fish oil diet, serum EPA and DHA concentrations were significantly increased by week 1 and remained increased for 7 (DHA concentration) or 3 (EPA concentration) weeks after dietary fish oil supplementation was discontinued.
In dogs, supplementation of the diet with fish oil may have effects for several weeks after dietary supplementation is discontinued.
Studies of the effects of fish oil supplementation that use a crossover design should allow for an appropriate washout period.