COLIC                                                                                             PRINT PAGE

Most people have heard about colic, but what exactly is it?

Colic is not a disease but a symptom of the horse experiencing extreme pain in the abdominal cavity. The pains can originate from all the organs of the abdominal cavity, but often they originate in the gastrointestinal system. Various ailments of the gastrointestinal system produce more or less strong pains. The horse shows it by
  • refusing to eat
  • pawing with his frontleg
  • lying down and rising up again
  • rolling
  • flehmen response (upward-turning of the upper lip)
  • trying to defecate without result
  • kicking himself in the abdomen with the hind leg
  • sweating
  • high respiration

The horse may display some of these signs without actually colicing, but if he displays several of them there may be abdominal pain.

Should the horse display these signs, it is normally wise to walk him. This may start the gut activity. If there is no improvement after 10-20 minutes, then the veterinarian should be called. While waiting the horse can be relieved by massaging the horse’s ears and abdomen.

If the horse merely refuses to eat, take his temperature, the temperature of a grown horse should be around 37.5 to 38 degrees centigrade or 98 Fahrenheit.



When the veterinarian arrives the horse’s cardiovascular system and rectal temperature are examined and its abdomen is auscultated to determine whether the guts are rumbling and thus working. Then they are examined via the rectum. This way the veterinarian can feel whether the horse is impacted, has air in the guts, diarrhoea or a twist colic. The pulse rate is an indication of the horse’s level of pain. However, Icelandic horses are so “tough” that their pulse rate does not exceed much over 60 beats per minute, before the horse is very ill. Normally the pulse rate at rest should be around 28-38 beats per minute.

Gastrointestinal diseases occurs when the horse is fed with wrong feed, gets too much feed or if there is a sudden change in feed. Colic is also seen, if the horse eats frozen grass after the first night frost or eats too much straw in the stall.

Impaction stops the gut activity and when auscultated there is very quiet. Horses with impaction must have a tube inserted through the nasal cavity and down into the stomach in order to pour liquid paraffin (or oil as is traditionally used in North America) and large quantities of water into the intestinal system to dissolve the impaction. At the same time medicine given to make the guts re-activate and to reduce the pains. A severe impaction of the colon can be in progress for 1-4 days, and it may last up to 12-24 hours before the horse defecates normally again.

Tympanitic colic occurs when the bacteria in the guts develop too much gas, which can not escape. The gas accumulates and the horse is in a lot of pain. As a rule there are excess gut sounds, the treatment is anti-spasmodic medicine and analgesic as well as food supplements to restore the normal composition of intestinal bacteria.



Paralysis of the gut sometimes occurs without explanation. The guts stop moving and there is an accumulation of gas. There are no gut sounds from the abdomen. The horse is given medication which cause the intestinal muscles to retract so they start working again.

Twist colic is a very serious ailment where the intestines are twisted in the abdomen so there is no passage of intestinal content. The colic symptoms are violent, the pulse rate high and the gut silent. In a majority of cases, surgery on the horse is necessary to save him and it should take place immediately. Luckily, this ailment is very rare compared to other types of colic.

Diarrhoea can occur from consumption of cold humid grass, silage, or worm larvae embedded in the intestinal lining, especially during the winter. These larvae can emerge from the lining and cause diarrhoea in the horse. The diarrhoea is best treated with dry hay, medication to re-establish the normal composition of the intestinal bacteria and perhaps cortisone and a dewormer, if there is suspicion of worm larvae. Some horses simply cannot eat silage or haylage, they constantly get diarrhoea. They should be fed with dry hay.



Stomach ulcers seems to be more common than previously known. However, no studies in Icelandic horses have been made yet, but I have encountered a couple of severe cases where the symptoms were colic and fever. Mild stomach ulcers can display a variety of symptoms and can be difficult to detect. Some of the symptoms can be lack of or varying desire for eating nutrients, reduced performance, stressful behaviour or minor colic pains. To examine the horse for ulcer a long gastro scope must be inserted into the horse’s stomach to view the lining. It is important that the horse has fasted for 48 hours prior to the gastroscopy, otherwise there will be too many food particles in the stomach impairing the view of the lining.



Botfly larvae has become a serious problem in Denmark now where dewormers are given in lesser quantities due to the prescription rules. According to my experience, all horses should be dewormed during the winter months in order to kill the botfly larvae, irrespective of the results of the worm tests. This is of course a controversial statement, however, having learned of a case where a 6-months-old foal died of starvation because his stomach and esophagus were so full of botfly larvae that he could not swallow, I think that the problem should not be neglected. The horses were currently monitored with worm tests, but in such tests the number of larvae cannot be detected. (In North America you can buy wormer over the counter and don’t need a prescription).

If you have a horse with colic pain always contact the veterinarian, as it may easily develop into a serious matter, if the horse is not treated in due course.

Rikke Schultz
Equine Veterinarian

Hørsholm Hestepraksis (The Equine Veterinary Clinic in Hoersholm).