Help for Heaves in HorsesBy Kentucky Equine Research Staff · February 16, 2016
Inflammatory airway disease in horses, often referred to as heaves, robs horses of their potential as athletes. Subtle signs mark the onset of disease—the occasional cough, an intermittent wheezing, a nearly imperceptible change in stamina. The progressive nature of heaves eventually leaves many horses with exercise intolerance so severe that a career change or retirement is necessary, though this doesn’t typically occur for years after diagnosis.
Researchers have confirmed that severity of disease signs coincide with significance of airway inflammation on endobronchial biopsy. In a study* conducted at the Université de Montréal, Canada, researchers studied 18 horses, 6 of which were healthy and 12 of which had heaves. Of the 12 horses with heaves, 6 were not showing clinical signs of the disease, while the other 6 were experiencing typical signs. Multiple endobronchial biopsies were taken from each horse, and blind assessors scored the biopsies based on predetermined inflammatory and morphological parameters. Biopsy scores revealed that horses with active heaves had significantly more disease than remission or control horses.
Because outward signs mirror inflammatory severity, horse owners can employ specific management strategies to deal with heaves and determine immediately, sometimes within mere hours, if these tactics will provide relief to the horse.
A common practice involves moving stalled horses to an outside environment completely or extending the number of hours horses spend outside. If that is not possible, maximizing ventilation in a stall and bedding with low-dust options such as wood byproducts can help affected horses. In addition, purchasing clean hay, with no sign of dust or mold, and then wetting, soaking, or steaming it just prior to feeding reduces inhaled particles.
Though a veterinarian should be the first-call professional in dealing with chronic heaves or respiratory issues of any kind, a simple dietary change may help keep acute episodes from occurring. “One nutritional supplement that has garnered widespread attention in the fight against heaves is omega-3 fatty acids, which have well-known anti-inflammatory properties,” said Catherine Whitehouse, M.S., a nutritionist at Kentucky Equine Research (KER).
Probably the most common omega-3 supplement is flaxseed or flaxseed oil, plant-based feedstuffs, though fish oil is gaining in popularity. Fish oils are direct sources of DHA and EPA, which are the most useful omega-3 fatty acids in terms of conferring health benefits. Flaxseed and its byproducts contain ALA, which must then be converted to DHA and EPA, a complicated and inefficient process. For optimal omega-3 supplementation, therefore, use a marine-derived source such as EO•3, advised Whitehouse.
*Bullone, M. 2015. Endobronchial biopsy scores reliably assess disease severity in horses with heaves. American College of Veterinary Internal Medicine Forum, Indianapolis, Ind., June 3-6.