"I think your horse has colic." Words to strike fear into any horse owner's heart. But what is colic? What signs should you look for?

Colic refers to pain originating in the abdomen. Generally horses do not tolerate abdominal pain very well. So if there is any disturbance of gut function they tend to show signs of pain.

Signs of mild discomfort might be stretching, standing as if to urinate, and pawing the ground. If he is more painful the horse will get up and down, and roll to try to get more comfortable. He will start sweating. More serious cases will get up and down and roll constantly.

If you think your horse has colic, you should call an experienced equine vet straight away. He or she will be able to provide emergency pain relief and decide whether further treatment is necessary.

What can you do while you wait for the vet to arrive? Taking your horse for a walk often helps. It may encourage his guts to work normally and soothe the pain. It may also prevent him lying down to roll. If he is lying down quietly then let him stay there.

It used to be thought that a horse could cause a twisted gut by rolling. That is probably not true. But it is best to prevent him rolling if you can. That way you will prevent him injuring himself by banging himself on the stable walls. But be careful that you don't get injured yourself. Horses often forget all their normal manners when they are in pain.

There are many different reasons for horses to get colic. But often the signs look similar regardless of the cause.

What will the vet do to investigate the problem? He or she will listen to the abdomen with a stethoscope to tell whether there is more or less activity in the gut than normal.

The heart rate gives a good indication of the severity of the pain and the seriousness of the problem. A horse with a normal heart rate probably does not have a serious problem. Whereas a high heart rate is not such a good sign.

A very useful part of the examination is the rectal examination. By feeling the intestines, the vet may be able to identify the cause of the problem. It goes without saying that this is a very skilled procedure, that is potentially hazardous for both the vet and the horse. But for an experienced equine vet the information it gives is invaluable in deciding the nature of the problem. It may reveal a blockage, or a swollen loop of intestines as a result of a twist or other intestinal catastrophe.

In all but the most straightforward cases the vet may pass a tube through the nose into the stomach . It sounds unpleasant but often may make the horse more comfortable by releasing the pressure in the stomach. It can also give the vet useful information about whether the stomach is emptying properly.

Sometimes the horse is in so much pain that it is impossible for the vet to examine him properly without first giving a dose of sedative or pain killer.

Only by considering all of the signs revealed by a careful examination is the vet able to make a tentative diagnosis. Even then it may not be possible to tell exactly what is going on.

Sometimes, after the first examination, it will be apparent that the horse needs emergency surgery. But more usually the vet will decide to treat the horse with a short-acting pain-killer and review his condition after a couple of hours. Most cases show a rapid improvement. But some will either not respond to the treatment, or they will improve at first, only to start showing signs of pain again later.

Rather than having to call the vet out several times, it is usually better to transport these cases to a specialist equine practice where they can be monitored closely and surgery can be performed if necessary.

Fortunately the vast majority of cases respond to medical treatment. But if surgery is needed - it is important to operate early. The chance of a successful outcome is much better if the operation is carried out before too much damage has occurred.