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.

The research studied the effects of certain dietary supplements on horses suffering from seasonal pruritus (itchiness), comparing the impacts of evening primrose and fish oil versus hydrogenated coconut oil. It was found that although the overall clinical conditions remained the same, there were significant variations in specific fatty acid levels in the horse’s bloodstream according to the supplement given.

Research Methodology and Subjects

• The double-blind, placebo-controlled trial involved a total of 33 horses diagnosed with recurrent seasonal pruritus, which is a condition characterized by persistent and intense itchiness.
• The areas primarily affected by pruritus in these horses included the mane, tail, head, and rump.

Interventions and Measurements

• The horses were either treated with a combination of evening primrose and fish oil or were given hydrogenated coconut oil. These treatments were administered in test and placebo capsules respectively.
• The investigation spanned a period of 24 weeks, with analysis taking place at the start, midpoint (12 weeks), and end of the experiment.
• Various types of fatty acids in the plasma phospholipids were measured, including linoleic acid, dihomogammalinolenic acid, alpha linolenic acid, and others.

Results

• There was no observable difference in the overall clinical condition of the horses, irrespective of whether they were administered test capsules or placebo.
• Horses in the test group displayed a significant reduction in linoleic acid and a substantial increase in other fatty acids such as dihomogammalinolenic acid and alpha linolenic acid.
• Horses in the placebo group also showed significant changes in fatty acid levels, with reductions in linoleic acid, dihomogammalinolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid and an increase in dihomogammalinolenic acid.
• The study found noteworthy differences between the test and placebo groups in plasma phospholipid concentrations for dihomogammalinolenic acid, docosahexaenoic acid, and alpha linolenic acid at specific points during the 24 week trial.

Conclusion

• Despite the overall clinical conditions of the horses remaining relatively stable, administration of evening primrose and fish oil or hydrogenated coconut oil resulted in noteworthy changes in plasma fatty acid concentrations over the test period.
• This suggests that the type of dietary supplementation can have varying effects on the physiological response in horses suffering from seasonal pruritus.