A study was performed to investigate the effect of diets rich in polyunsaturated fatty acids and other related nutrients, in the effort to improve skin and hair coat conditions in canines. The study included 24 dogs fed a baseline diet (Ol’Roy®), with an acclimation period of 12 weeks (Phase I). Nine female beagles and 15 male hound mixed-bred dogs were used. For the next 12 weeks (Phase II) the dogs were randomly divided into three groups and fed one of three specially formulated complete and balanced diets.

Differences among the three diets were as follows: Diet A contained lower but adequate amounts of dietary zinc and linoleic acid than Diet B. Diet C was similar to Diet B with respect to zinc but contained less linoleic acid and more alpha-linolenic acid. In the beginning, a preliminary study assessing skin lipids showed that hair is a suitable material to analyze. This study lead to the subsequent investigation, using plucked and shed hair samples obtained on weeks 3, 7, and 11 (Phase I) and again on weeks 1, 3, 7, and 11 (Phase II).

One objective of this research was to investigate the dietary effects of the combination of linoleic acid in combination with zinc on canine sebum lipids during a 12 week diet phase. Another objective was to investigate if any correlation existed between the hair cycle anagen and telogen phase of the hair follicle and the lipid constituents present in the sebum during the 12 week acclimation phase and the 12 week feeding trial.

Two hypotheses were tested. First, the lipid content of hair can be altered by fat and fatty acid composition of the diet. Second, the modification of dietary fat and polyunsaturated fatty acids lead to changes in hair lipids that may be related to improved skin and hair coat scores.

Over the 12 week feeding period of Phase II, test results revealed statistically significant increases in both CE and CE/WD, and a prolonged growth of hair follicles in the anagen phase of diet B dogs, which are both consistent with improved skin and hair coat scores.

PubMed 17542730
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