18/09/2026
Saw this and had to share — worth a read. What do you all think?
*** AMMONIA; THE LESSER KNOWN CAUSE OF RESPIRATORY INFLAMMATION IN HORSES ***
“That” smell. The smell we all try to avoid exposing the general public to, when it’s stuck to our clothes. The smell that even sticks to our hair after being in a smelly stable. Ammonia.
Ammonia shouldn’t be considered a normal smell in a stable. At high levels, prolonged exposure to ammonia is dangerous.
HIGH LEVELS OF AMMONIA CAN BE FATAL. Yes, it’s that corrosive, and that much of an irritant. If you don’t believe me, then look it up. Even if you are briefly exposed to concentrated levels of ammonia - 1500ppm - it has the potential to cause serious health issues, including IRREVERSIBLE LUNG DAMAGE.
Ok, we are obviously not going to die due to ammonia levels caused by our horses’ urine, but if we look further, we find that the average level of ammonia in a normal stable, 5-10ppm, is definitely enough to cause respiratory inflammation.
Ammonia levels are highest near barn and stable floors, for obvious reasons. Horses obviously frequently sleep on the stable floor, where that high level of ammonia is. This is why it is SO important to have a very absorbent bedding. In my experience and opinion, although straw beds look fluffy and inviting, they are the least absorbent bedding you can use. Straw beds often leave your hair and clothes absolutely stinking of ammonia. One option would be to use a very absorbent base, such as small flake shavings, or Aubiose, and then put your fluffy straw bed on top. Or ensure you remove the wet on a daily basis from a straw bed, and allow the smelly wet floor to dry before laying the clean bed. The same goes for big flake shavings, which although significantly less dusty than small flake shavings, are extremely non absorbent.
Horses often eat hay from the floor, and if this is how you feed your hay, you need to be extra careful to ensure that you keep ammonia levels low in your stable.
Exact levels of ammonia that are significantly detrimental and harmful to horses, are currently unknown. However…..we do have some stats.
Research has shown that ammonia levels in a normal barn/yard, with stables mucked out well, is around 200ppm AT FLOOR LEVEL. So why do we need to worry at all, as that is way off the 1500ppm that will cause irreversible lung damage in humans with very brief exposure? We have to worry because our horses are often in their stables for long periods of time. We definitely aren’t talking “brief” exposure. Therefore, 200ppm is worrying if we are exposing our horses to it for 12 hours a day, or more. Again, this 200ppm was at floor level, so not as much of a concern if horses are eating from haynets, and spend most of their time standing. But still something that should be controlled as much as possible.
Another human stat, is that the US Occupational Health has a set a FIFTEEN minute exposure limit for humans for gaseous ammonia levels of only 35ppm. I’ll leave you to digest that. 200ppm is “normal” at floor level in a barn full of horses. Our respiratory tracts aren’t that different, and their lungs are much bigger.
I have never used a bedding as absorbent as Aubiose Horse Bedding. Yes, I am fortunate enough to be sponsored by Aubiose, but I genuinely used it BEFORE I was sponsored by them, and I’d 100% continue to use it if I wasn’t sponsored by them. It contains very little dust, and is very absorbent. No bedding is completely dust free, and I want a bedding that is as dust free as possible, but at the same time extremely absorbent, to keep ammonia levels as low as possible.
I will conclude by repeating that we don’t yet know what concentration of ammonia is needed to damage horses’ respiratory tracts. Current research shows that horses that eat from a good height above the ground, and spend most of their time standing, are not exposed to extremely high levels. BUT we still don’t know what concentration will cause inflammation in horses.
We do know that ammonia inhalation in horses DOES result in excessive mucous production in the trachea, and narrowing of the airways. AMMONIA INDUCED AIRWAY DISEASE does exist.
As in my first respiratory article, PREVENTION IS BETTER THAN CURE.
Feel free to share.
Photo of one of our beautiful Aubiose Horse Bedding beds!
