Q: I am looking for some practical solutions for managing my horses’ stalls. They are 24 by 24 feet and exposed to the elements with the exception of an eight- by 12-foot three-sided covered area. My mare’s urine builds up in her covered stall, and—although it is exposed to the open air— to a horse’s lungs. How can I eliminate the odor? I’ve tried stall powders, which work but get expensive. Name withheld by request

A: Ammonia is a gas produced from nitrogen found in equine waste. It is a well-known respiratory irritant in people and horses, and you are wise to be concerned—if you can smell ammonia in a stall, it is likely present at harmful levels.

There are products, as you mentioned, that are very effective and can absorb the ammonia and reduce the horse’s exposure. Assuming you are already cleaning stalls daily, providing additional bedding may also help reduce the ammonia odor. If you haven’t already, you may want to install mats in the covered area of the stall. The mats, and the bedding you put on top of them, will keep the urine from soaking into the soil.

It is also possible that your mare’s urine contains excess nitrogen waste because she gets too much protein in her diet. You might consider consulting a nutritionist to ensure your horse’s diet is properly balanced.

Shannon Pratt, DVM
North Carolina State University
Raleigh, North Carolina