Date of Award


Degree Type


Degree Name

Master of Science (MS)


Veterinary Clinical Science

First Advisor

Laurent L. Couetil

Committee Co-Chair

Laurent L. Couetil

Committee Member 1

Joanne Messick

Committee Member 2

John Burgess


Chronic lower airway inflammatory diseases, such as recurrent airway obstruction (RAO) and inflammatory airway disease (IAD) are common in horses. RAO and IAD present many similarities with asthma in people. Based on studies in human asthma, omega - 3 polyunsaturated fatty acid (PUFA) supplementation has been proposed to improve clinical signs in horses with chronic lower airway inflammatory disease. The purpose of this study was to evaluate the clinical efficacy of an omega-3 PUFA containing equine feed supplement (AleiraTM) in horses with chronic lower airway disease. The study consisted of two separate experiments. First, a pilot study was performed in 8 research horses owned by Purdue University, to find the minimal effective dose that is able to alter the composition of phospholipid classes in plasma. Once the minimal effective dose was identified, a randomized, double blind, placebo controlled clinical trial was performed on client-owned horses with a history of chronic cough (>1 month). Eligible horses were randomly assigned into one of 3 treatment groups fed daily for 2 months with: 30 g of the supplement, 60 g of the supplement or 30 g of placebo. Additionally, all horses in the study were maintained on a complete pelleted diet for the duration of the study with no exposure to hay. Multiple clinical and clinicopathologic parameters were measured, as well as lung function testing was performed before and after the 8-week supplementation period. Data was analyzed using Wilcoxon matched pairs test. Data were expressed as median [25th-75th percentiles] and P