The burning in the respiratory system is caused by the buildup of noxious gas from naturally degrading horse urine, but there’s nothing necessary about it.
Here, we look at the problems caused by ammonia and possible ways to make barns safer for you and your horses.
Breakdown of Ammonia
Let’s start from the beginning and look at how ammonia ends up in your horse’s stall. First, excess protein from the diet is expelled from the horse’s body
through urine in the form of urea. Each time a horse eliminates its bladder, 1-1 gallons of urine floods into the stall.
“No amount of bedding, no matter how absorbent it is, will catch that much urine,” Hayes points out. “And, the problem is the urine that gets away.”
The escaping urine trickles through the cracks of the stall mats, down the stall drain, or into overly deep bedding. Once trapped in these dark, oxygen-devoid
areas, naturally occurring anaerobic bacteria get to work feeding on the nutrients of the urea-rich liquid, and the resulting by-product is ammonia.
Ammonia is a pungent-smelling, highly flammable gas, which is colorless at room temperature. It has commercial uses as a refrigerant and in the
manufacturing of fertilizer, plastics, and explosives. Ammonia gas is also highly soluble in water and is used in solution as a cleaning agent.
The presence of ammonia produced from horse urine gives barns their notorious smell. While ammonia is a struggle for horses and their owners when trapped
in barns, the substance otherwise plays a purposeful and natural role in the environment. The interaction of bacteria and ammonia is an integral part of the
nitrogen cycle, the natural path nitrogen takes to cycle from air through soil before being taken up by plants and returned to its original, gaseous form.
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 mold in feed and bedding played a part in
pulmonary problems, Hayes believes exposure to ammonia also negatively impacts their respiratory systems.
She notes that ammonia is a caustic gas. “Besides just being unpleasant in a barn, ammonia gas burns the delicate tissues of the respiratory tract and the
eyes and increases mucus production,” Hayes says.
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.
Due to the negative health impact of ammonia exposure on humans, the U.S. Department of Labor’s Occupational Safety and Health Administration includes
ammonia on its list of toxic and reactive highly hazardous chemicals. According to OSHA regulations, employers cannot expose construction workers to
ammonia concentrations of more than 50 ppm.
“That ruling was not chosen arbitrarily,” Hayes points out. “It was based on the established long-term, chronic effect on the respiratory system and the eyes.”
Hayes became curious about ammonia levels in horse barns after seeing the OSHA standard. Following the guidelines set by OSHA, she started testing stables
using a Drager, a small, bellow-like tool that takes air-quality samples. The results surprised her. “I’ve gone to fancy, multi million-dollar show barns, lifted
up mats, and measured ammonia levels at 450 ppm,” she says.
Whether a barn houses high-end performance horses or trusted lesson ponies, ammonia takes its toll on the animals’ athletic abilities and their overall quality
of life. The cough related to chronic obstructive pulmonary disease (COPD), or heaves, is often considered an unavoidable result of aging, but research
suggests these conditions are exacerbated by ammonia exposure, says Fredrick Harper, PhD, equine extension specialist for the University of Tennessee’s
Department of Agriculture.
“If you have horses with the propensity for respiratory problems and put them in stalls with high levels of ammonia, you aggravate that situation,” he says.
High ammonia readings at floor level are especially troubling for foals, which spend a majority of their days sleeping at their dams’ feet, says Harper. A 2000
University of Kentucky study examined bedding foaling stalls with straw and cleaning the stall daily. Over a two-week period, ammonia at floor level rose from
2.5 to 228 parts per million (ppm).
“It’s been suggested that a level of just 10 ppm causes problems in other animals, such as calves,” Harper says. “It appears that levels in horse stalls are
probably so much that we might be challenging or damaging foals.”
There are however solutions for this health risk, such as Stall Genie Products, which reduces Ammonia in Stalls, and provides your horses with a clean, healthy bedding and living environment.
If you are interested in purchasing Stall Genie Products – please enter our online store by clicking the button below.