A double-blind placebo-controlled trial of an evening primrose and fish oil combination vs. hydrogenated coconut oil in the management of recurrent seasonal pruritus in horses

Clinical status and plasma phospholipid fatty acids of 33 horses with seasonal pruritus were investigated following fatty acid supplementation. Principal areas affected by pruritus were mane, tail, head and rump. There were no significant differences in clinical status between horses receiving test and placebo capsules. Horses receiving the test preparation showed significant reduction (weeks 0-12) in linoleic acid (P < 0.05) and significant increases (weeks 0-24) in dihomogammalinolenic acid and alpha linolenic acid (P<0.05). Placebo-treated horses showed significant reductions (weeks 0-12) in linoleic acid, dihomogammalinolenic acid, arachidonic acid (P < 0.01), eicosapentaenoic acid and docosahexaenoic acid (P < 0.05) and a significant increase (weeks 0-24) in dihomogammalinolenic acid (P < 0.05). Significant differences in the change in plasma phospholipid concentration between test and placebo groups were seen for dihomogammalinolenic acid and docosahexaenoic acid (P < 0.01) between weeks 0 and 12 and for alpha linolenic acid (P < 0.05) between weeks 0 and 24.