Omega-3 fatty acid supplementation provides an additional benefit to a low-dust diet in the management of horses with chronic lower airway inflammatory disease

J Vet Intern Med. 2015 Jan;29(1):299-306. doi: 10.1111/jvim.12488. Epub 2014 Oct 10.


Background: Omega-3 polyunsaturated fatty acid (PUFA) may benefit humans and animals with chronic inflammatory diseases.

Hypothesis: Omega-3 PUFA supplementation improves clinical signs, lung function, and airway inflammation in horses with recurrent airway obstruction (RAO) and inflammatory airway disease (IAD).

Animals: Eight research horses and 35 client-owned horses.

Methods: A pilot study examined the dose of PUFA that can alter plasma PUFA composition. Then, a randomized, controlled clinical trial was performed in horses with RAO and IAD. Horses were fed a complete pelleted diet with no hay and randomly assigned to 1 of 3 daily treatments for 2 months: 30 or 60 g of the supplement or 30 g of placebo. Clinical signs, lung function, plasma PUFA composition, and bronchoalveolar lavage fluid (BALF) cytology were evaluated. Data were expressed as median (25-75th percentiles). P < .05 was considered significant.

Results: Polyunsaturated fatty acid supplementation resulted in increased plasma docosahexaenoic acid (DHA) that peaked at 4 weeks. Clinical improvement was noted in all horses involved in the clinical trial, but the group that received PUFA had greater improvement in clinical signs (cough score improved 60%), lung function (respiratory effort decreased 48%), and BALF (neutrophils decreased from 23 to 9%) when compared to placebo (cough score improved 33%, respiratory effort decreased 27%, BALF neutrophils increased from 11 to 17%; P < .05).

Conclusions and clinical importance: Feeding horses with RAO and IAD a PUFA supplement containing 1.5-3 g DHA for 2 months provides an additional benefit to low-dust diet.

Keywords: Cough; Inflammatory airway disease; Poor performance; Recurrent airway obstruction.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Feed / analysis*
  • Animal Nutritional Physiological Phenomena
  • Animals
  • Bronchoalveolar Lavage Fluid / cytology
  • Chronic Disease
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Dust
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / pharmacology*
  • Female
  • Horse Diseases / drug therapy*
  • Horses
  • Inflammation / veterinary*
  • Lung Diseases, Obstructive / drug therapy
  • Lung Diseases, Obstructive / veterinary*
  • Male
  • Pilot Projects


  • Dust
  • Fatty Acids, Omega-3