Why does my horse cough when he runs?

When was the last time the vet examined your horse? I would have him looked at, especially since you say it isn't a cold. Lungworm is a possibility. But it sounds more like Heaves. It is usually caused by an allergy, but heaves does not go away even if the source of the allergy is removed. Do you have chickens? A lot of times heaves can be caused by an allergic reaction to chicken dander. If it is heaves wetting your horse's hay will help.

This is mom that asked the question. We feed our horses 12% sweet feed and its siminul blue ribbin so its very good feed. They get TNA hay. So he does not have heaves cuz the hay is real good. He is not over worked. My mom rides him every weekend. He cant have a cold this is just something hes always done everytime he gallops even without the rider. We ride at colt creek so its all grass the pasture is all grass so he aint coughin from dust. HAHA karen thats funny!

Maybe he has the Swine Flu. I would call the vet immediately!

I agree there may be several issues involved (dust, allergies etc.).

To be on the safe side you may also want to have a vet check him for lungworm.

Good luck with your horse. I hope they get over the problem so they can enjoy running without the annoyance.

i agree with the heaves. if we had a horse we wet down the hay not soaking of course. i am not sure why this helped but it did.so try it

It could be several things, the simplest being allergies. It could be from dust in the paddock, or if you are turning up a lot of dust when you gallop him. It could also be from dusty hay. To test the hay pick up a flake or two and drop it ... if you see a cloud of dust, that tells you for sure it's probably the hay, if no dust then pick it up and take in a deep breath of it, if it smells green and fresh then there's no problem with your hay. If it smells really dusty or musty then it could be either really dusty or moldy.

it could also be that your horse has a cold. If you see a runny nose try giving some cough medicine or ask your vet if it persists. If a horse has a cold and you work them excessively (galloping etc) you could cause them to cough more and cause airway damage so be careful until you rule out a cold.

More sever would be equine chronic obstructive pulmonary disease. This resembles asthma or bronchitis. In it's earlier cases can be referred to as "heaves" or "wind-broken" as mentioned above. It can be mild or get pretty bad, but just because you have a mild case doesn't mean it will get worse. Many times you can manage it. A first test would be to look at your horse standing (before exercise) from the side. You want to look at the lower part of his belly past his ribs. when he breaths normally there should be a very little rise and fall there, if you can see a dominant line develop as the horse breaths out (and his belly kind shakes) this would be a heave line. Until you know it well it may be hard to see. On severe cases you would also hear the horse make a whistle type wheeze when he breaths out.
If you can't tell from that, another test you can do is to carefully, rub up and down the horses throat, gradually increasing the pressure you put. If the horse is having troubles breathing they will cough, if not then it's just allergies or a cold etc. (you may want to ask someone who knows how to do this such as an experienced friend or a vet, especially when testing around the throat you don't want to cause more damage).

If the horse has heaves, and it is mild you can still ride them and it wont cause further damage, of course if the horse is having troubles breathing you should stop.

Here are some solutions to try to eliminate the coughing.

If your hay is dusty, wet it. sometimes just wetting it a little will work, other times you need to soak it for a while. *if you suspect heaves make sure you have a removable bin to put the soaked hay in, a lot of people will just put it on the floor DON'T, the water from they hay will soak into the cracks of your stall, causing mold with the dust and sawdust around the corners making this worse (we tried soaking Tex's hay and we had to stop because of that).

Take a look around your barn, is there open insulation anywhere near your horses stall, or other places where mold or dust might collect.

Check the grass your horse is eating.... It sounds crazy, but this is what made Tex sick in the first place, grab handfuls of the grass and smell it. It should smell sweet and grassy. If it has any musty or rotten smell, don't allow the horse to eat it. This usually happens in places where lots of water collects in a field, if it is constantly damp it runs the risk of developing mold.

Before worrying about heaves make sure you rule out everything else, it's always a good idea to try to remove the dustyness and mold away too, it's a simple and easy precaution.

is it dusty where you gallop him.? It might be that he gets dust and coughs.

My 29 year old thoroughbred often coughs a couple of times when he runs in from the pasture. I attribute it to once when I had some hay that I later realized was somewhat moldy. A horse that is "wind-broken" may cough too, or one that has "heaves". Heaves are usually from bad hay or grain, but they have a lot of symptoms like breathing strange, kinda sucking up their stomach and then dropping it. If your hay is dusty your horse may cough too. If your horse has just clear moisture coming from his nose and it isn't snotty I wouldn't think he had a cold. If it persists, I would call and ask the vet about it.