Coughing in horses explained

We explain the different types of coughing your horse might suffer from and the symptoms to look out for. 

More time in the stable can be a cause of winter coughing

More time in the stable can be a cause of winter coughing

Winter is a common time for horses to cough because they’re inside so much, and this is especially true if they’re in barn-style stabling, which pre-disposes them to spreading infection.

This is exacerbated by the fact that colder temperatures and condensation make horses more prone to picking up a respiratory infection.

What are the causes of coughing in horses?

The causes of winter coughs tend to be either environmental or an infection, but in a small number of cases there can be a viral cause.

Environmental causes include dust, mould or spores from hay or bedding, which get into the lungs and cause inflammation in the lower airways, leading to coughs or causing irritation that allows infections to set in.

Infections (often streptococcal) can be spread through coughing or sneezing when animals are sharing air space, especially if there’s not enough air turnover.

Low temperatures cause horses’ expirations to form very small droplets, which can find their way deep into the lungs.

The larger droplets found in warmer weather can be filtered by the turbinates within a horse’s nose and head. Phlegm or snot produced by an affected horse can spread infections, and viruses such as influenza can also be spread this way.

What are the symptoms of coughing?

Coughing during exercise

If a horse coughs at first and then appears fine the cause is likely to be environmental, but if the coughing persists it usually signals the presence of an infection.


If you find phlegm outside your horse’s door or on the floor of the stable it’s likely he has a productive cough as the result of an infection within the lungs.

Signs of general ill-health

A horse who appears depressed, is off his food or has a high temperature may well have a respiratory infection

Nasal discharge

Nasal discharge can be the sign of a problem. Here’s what’s normal and what’s not:

  • Clear or white: Don’t worry just keep an eye on his breathing
  • Yellow out of both nostrils: This could be anything from an allergy to strangles, it depends on the rest of your horses symptoms, if he is under the weather, call the vet.
  • Yellow out of one nostril: Usually a sinus infection or tooth abscess, call the vet.
  • Green: A rather advanced infection probably from somewhere in the respiratory tract.

How to prevent your horse from coughing 

Reduce the chance of your horse contracting any respiratory diseases this winter by taking note of these quick tips


Is your bedding dust free and how often do you take out the wet? You don’t want to be cleaning it all out too frequently if it's shavings because the wet prevents dust from forming.

If your horse is susceptible to dusty bedding, have a look at alternatives to straw such as Aquamax, Verdo, Bedmax or Easibed, which claim to be virtually dust free.

You should also avoid mucking out with your horse in the stable, tie them up outside or put them into a different stable for 10 minutes.


Soak hay for five minutes to avoid the risk of your horse inhaling dust. You should also feed it to your horse immediately after soaking.

A lot of people make the mistake of soaking their hay in the morning then feeding it to them at night.

Doing this is nearly worse than not soaking it at all because while the hay sits there, slightly damp all day, it's the perfect environment for microbes to grow. 

A hay steamer is a good idea if it's within your budget. Steam ‘n’ Easy, Happy Horse and Haygain all receive the thumbs up from us as far as hay steamers go.

Hay steaming

Hay steaming is scientifically proven to kill all dust spores in hay, helping to prevent respiratory problems.

Soaking has previously been the conventional method to dampen down the spores, but it doesn’t remove them completely.

Also, when feeding a horse out of a hay net, the hay dries out encouraging the spores to become airborne again. It’s always better to feed a horse off the floor in its natural grazing position, which also allows his airways to drain more efficiently.


Your horse’s stable should have plenty of ventilation and if possible, nowhere near the hay room.

You can gauge how well ventilated your stable is by looking for cobwebs. Spiders don’t like ventilation so if they’re sharing your stable, chances are your horse could do with a bit more air. 


We all know how much you love sweeping, it’s therapeutic to say the least, and there’s nothing better than a well-swept yard.

If you’re one of these people, think about how your horse feels if he’s in the line of the dust that you’re blowing his way too.

When grazing with his head down your horse can drain his airways efficiently

When grazing with his head down your horse can drain his airways efficiently

Turning your horse out

The simplest thing you can do is turn your horse out where he's away from the dust and his head is in a natural grazing position.

If you're lucky enough to be in the position to turn out, make the most of it and let him have a good potter around his paddock.