Mitigating Respiratory Risks for Our Stabled Horses
Hay & Bedding
It is important we reduce exposure to allergens in the stable environment to aid respiratory health. We know that the majority of dust is brought into the stable in the form of bedding and hay.
Certain types of bedding and forage represent significant risk factors for equine asthma, with dry hay and straw not recommended. Straw can be a source of fungal particles closely linked to respiratory problems. The negative effects of this combination are magnified In American Barn set-ups with shared airspace. The best management regimen is to feed steamed hay and bed on dust-free shavings where possible (Auger and Moore- Colyer, 2017).
Daytime total and respirable particulate concentrations have been found to be nearly double the concentrations measured overnight, independent of management system, further reinforcing the impact of activity within the barn on particulate exposure. Where possible, muck out and sweep the barn when the horses are out in the field or being exercised (Ivester et al., 2014).
A horse’s urine contains urea, which is a by-product of the digestion and metabolism of protein in the horse’s diet. Urea is broken down by bacteria and off gases as ammonia.
Ammonia levels will vary depending on the stable set-up, ventilation, amount of urine produced by the horse, how often the stable Is mucked out/cleaned/disinfected and the flooring itself.
Highest levels are found 12” from floor level (80- 450ppm). Exposure levels of 220ppm for 10-30 minutes correlate to irritation of the respiratory tract, eyes and nose. This occurs at lower levels when horses are exposed for longer periods of time.
Ammonia production is often particularly high on deep bedding systems, in which wet matter is allowed to seep through layers of bedding to the subfloor. Without sealed flooring and/or heat or chemically treated bedding material, bacteria can accumulate and proliferate. The rule of thumb is that, if you can smell ammonia, it is already at a level that will irritate airways; yours and your horse’s.
A non-porous floor such as Comfortstall by Haygain enables you to muck out the wet bedding, remove all the urine and starve subterranean populations of bacteria that have been thriving on a steady supply of urea. As a sealed, one-piece flooring system, ComfortStall allows you to contain the urine and gives the bedding more chances to absorb it. It also allows for easy and efficient cleaning with disinfectant.
A 2001 study by the Equine Pulmonary Laboratory at Michigan State University’s School of Veterinary Medicine found that young horses stabled during training suffered respiratory distress when compared to pastured horses of the same age. While dust and mould in feed and bedding played a part in pulmonary problems, exposure to ammonia also negatively impacts their respiratory systems (Hayes, 2005).
It's not just horses who should be protected from high ammonia levels. In humans, ammonia exposure causes narrowing of the throat and bronchi, fluid in the lungs, eye irritation, nausea, vomiting, and dizziness. According to the North Carolina Department of Health and Human Services, extended exposure to ammonia fumes can cause chronic inflammation of bronchi, airway hyperactivity, and chronic irritation of the eye membranes.
For more tips on making the stable environment more natural and healthier for our horses, download Haygain's e-book "Optimizing the Stable Environment."