Why is my Horse Drooling so Much?

Why is my Horse Drooling so Much?

Health & Safety

Some horses really drool a lot even when they are in great condition and don't have any dental issues. It can be pretty messy when a horse starts to slobber because it goes all over the place! But why do some horses slobber more than others do?

Hyper-salivation or excessive drooling can not only be a bit messy especially if you are showing your horse or competing with them, but it could be caused by several things. The most common cause is something that's called slaframine toxicosis which horses do when they ingest any mould that's often found on red clover. The mould is called Rhizoctonia leguminicola fungus and when when horses are allowed to graze a clover rich paddock, they may well drool a lot. Once they are taken off this type of pasture, the slobbering usually stops.

With this said, if you feed hay that has a lot of red clover in it, this too could have the same effect and the result would be a horse that tends to drool more than usual simply because they are experiencing slaframine toxicosis from munching on their hay.

How to Spot Contaminated Clover

It's pretty easy to spot any contaminated clover in a paddock because the leaves have a grey tinge to them instead of the normal vibrant green colour they usually have. The leaves eventually turn black and although eaten in moderation, horses don't tend to be affected, if they are left on a paddock full of affected red clover, they will eventually start to slobber excessively. The reason is the bitter taste of the leaves irritates and stimulates their saliva glands.

Other reasons why a horse may drool more than usual include the following:

  • Horses with lesions on their tongues often drool excessively
  • Dental issues can result in horses slobbering
  • Abscesses in the mouth may cause a horse to drool
  • A foreign body lodged in a tooth will also cause them to drool more than usual

There are more serious reasons why some horses salivate which could be due to some kind of obstruction in their throats. Horses that suffer from gastric ulcers also tend to slobber more than usual.

Lots of horses and ponies tend to “work” their bits when being ridden which produces a lot of white slobber, but this is not something that you need to worry about too much. However, if you find that your horse is suddenly drooling a lot, you should contact the vet so they can check them out. There are around 18 reasons why a horse might hyper-salivate and a few of them are deadly albeit quite rare.

Normal Drooling in Horses

A horse has three pairs of saliva glands situated under their tongues and in their throats. Amazingly, they can produce around 10 gallons of saliva every day! Most of the time when a horse suddenly starts to hyper-salivate, it is due to an irritation which is more than likely triggered by some kind of chemical they have come into contact with. With this said, some oral wormers can trigger excessive drooling in horses and the same can be said for certain equine drugs.

When Should Excessive Slobbers be a Real Worry?

If you find that your horse has started to drool a lot more than usual and they have also lost their appetite or if you find they have real difficulty in swallowing anything, then you need to call out the vet as a matter of urgency. Other symptoms that may be cause for concern include the following:

  • If your horse starts to slobber and is feverish
  • If they are lethargic and drooling more than usual
  • If the slobber they produce has a thick consistency and looks weird

If you notice your horse shows any of the above symptoms, you would need to call out the vet so they can check your horse over. You may need to show the vet where you turn your horse out to pasture because something in their environment could be triggering this reaction apart from a red clover problem. The vet would need to rule out any sort of poisoning issues before recommending a treatment your horse if they feel it necessary.


Some horses like to play with their bit and often this can result in lots of drool around their mouths. A few horses when they turned out on paddocks where there is a lot of red clover often hypersalivate because of a mould that forms on the plant during the summer. Taking a horse off the paddock usually solves the problem although if any of their hay contains a lot of red clover, it could also trigger a reaction which results in excessive slobbering too. If you are at all concerned about the fact your horse is suddenly drooling a lot more than usual, you should call out the vet because there are more serious conditions that can cause horses to hypersalivate and which would need to be checked out.



Pets for studWanted pets

Accessories & services


Knowledge hub


Support & safety portal
Pets for saleAll Pets for sale