Ammonia is a stealthy compound that impacts even the most pristine equine facilities. A smell so powerful would normally cause a knee-jerk reaction in the brain’s amygdala region. But due to sensory adaption, our awareness of ammonia odor is reduced after prolonged exposure, causing us to dismiss it.


Urine – Sterile clear to yellow liquid from the kidneys that eliminates water, salt and other waste products not processed by the body into energy.

Ammonia – When excess protein is not metabolized by the horse, it’s shed in urine in the form of urea. Bacterial activity breaks down urea, creating ammonia gas, a chemical that burns the nostrils and lungs.


Ammonia is a caustic, corrosive gas that is poisonous when inhaled in high concentrations. Some signs of ammonia poisoning in horses and humans are:

  • burning, watery eyes
  • coughing
  • nose and throat irritation
  • difficulty breathing
  • nausea
  • vomiting
  • dizziness

Over time, ammonia poisoning can cause blindness, permanent lung damage and even death.


Many people think ammonia is a necessary component of the equine business. IT’S NOT! Tackling ammonia means implementing:

  • proper diet for your horse
  • good bedding
  • one-piece stall mats
  • stall amendments
  • proper cleaning
  • good ventilation
  • more turnout time
  • regular testing


A balanced diet equals less ammonia. Speak with your veterinarian or an equine nutritionist to make sure you’re providing your horse with the nutrients he needs.


Good bedding is a necessity for horses that spend a lot of time indoors. It provides absorption, moisture control, and acts as a barrier to noxious gases. Besides reducing the presence of ammonia, the right bedding can also help prevent high concentrations of mold, viruses, spores, bacteria, allergens, dust and endotoxins.


These lack seams, thereby minimizing the shifting, sliding and lifting that urine wetness
can seep through. Multi-seamed mats allow for urine puddling underneath, creating a temperate moist breeding ground for fungus and noxious ammonia.


Because ammonia needs moisture to produce odor, stall amendments can be of great benefit.


Keeping stalls clean and dry goes a long way to reducing ammonia. Increase the rate of cleaning during inclement weather or periods of greater barn occupancy during recoveries, etc. When you muck a stall, remove wet bedding and lay down a heavy dose of stall deodorizer. Apply fresh, dry bedding.


Passive (natural) ventilation means orientating barn doors and windows toward the prevailing wind and keeping them open to create airflow, perpetually renewing the air throughout the barn. Ceiling baffles, ridge vents and wall louvers are other options.

Active (mechanical) ventilation – the use of fans – isn’t common in horse barns, but can make the difference between a hot dank barn and a fresh- smelling one with low
ammonia levels. Strategically placed fans directed with the prevailing wind will pull heat, airborne pathogens, moisture, ammonia and carbon monoxide outside. Place fans high and out of reach in stall corners and on ceilings.


The more time horses spend outside, the less opportunity they have to urinate in their stalls. If your horse tends to urinate in one spot, try training him to pee mostly outside by placing his wet bedding outdoors where you want him to “go”.


In their article “How to Do Air Quality Testing in the Equine Barn”, Tuft’s University suggests testing stall air quality with a cyclone device or laser photometers. Otherwise, the best way to check the ammonia level in your barn is to get low and sniff!

While participating in an equine event, Theresa (Teri) Clark had a serious reaction to the dust in an arena warranting urgent medical care and was subsequently diagnosed with Asthma and COPD. Unwilling to stay away from her passion for horses, she began to research the topic and discovered that horses shared the same respiratory illnesses caused by dust, ammonia and pollutants. Teri is now dedicated to sharing how to control dust and other pollutants through education and by sharing her own line of natural products.


Equine Wellness Magazine is North America’s most trusted natural health and lifestyle magazine for horses, and the premiere publication educating a growing audience in natural and integrative approaches to health and horsemanship. EW transcends all areas of the equine market and appeals to everyone from backyard enthusiasts to serious competitors.