Colic is the term applied to abdominal pain in horses. While in people, tummy aches rarely amount to much more than a day or two of inconvenience, in horses they’re usually much more serious.
It is essential when colic develops that the cause be identified, as the life of the horse may well depend upon it.
While the likely outcome for some kinds of colic is good, in other cases the prognosis is poor.
If you ever question the need to worm your horses regularly, consider this: 90 per cent of colics in horses are caused in the first instance by parasites – mostly strongyles. These cause damage to intestinal arteries and reduce blood supply to the intestines. This lack of blood flow lowers the muscle tone in the area of intestine affected, which means a lowered ability to perform the muscle action, called peristalsis, that moves food material through the bowel. This sluggish peristalsis increases the risk of a blockage.
A blockage from any cause will, first and foremost, cause pain. This generally results from the bowel becoming distended from an accumulation of not necessarily only food material. It could also be gas or fluid. The pressure from this distension usually causes nearby bowel to go into a spasm.
The horse reacts to the obstruction and spasm by secreting fluid and digestive juices into the intestine. This fluid loss into the bowel can cause shock in the animal, which is just as likely to kill it as the colic. This dehydration needs to be treated in conjunction with the bowel obstruction.
Those with a colicky horse need to be careful if their horse shows signs of improvement without treatment. The muscles that spasm and cause pain eventually become tired and may relax, and the horse will be in less pain, possibly even appearing free from it. This is called paralysis of the intestine, or paralytic ileus. This is a serious development as the contents of the intestine, stalled in the bowel, begin to release toxins that can easily pass through the stretched intestine and poison the horse.
The symptoms for any form of colic are clear. A horse will indicate it is in pain, and the onset is often sudden in colic. It will sweat, paw at the ground, purse its lips, kick out, perhaps try to bite its stomach region. They may roll, perhaps assuming unusual positions in doing so. Classically, they may stretch out in a bid to relieve the discomfort. They may appear drawn up at the flank.
In some cases, depending on the cause, their pulse may be rapid – even over 100 beats a minute.
A horse showing symptoms of colic needs urgent treatment, or it may survive for only another 12 to 48 hours.
A vet will attempt to identify the cause of the colic, and the stage it is at. An accurate assessment here is vital to the right treatment being undertaken. A vet will most likely check the pulse, temperature, and overall condition of the horse. A lower than normal temperature will usually indicate that the animal is in shock and in need of rehydration. They will listen for bowel noise and may even perform a rectal examination. They may pass a stomach tube into the horse as the stomach gas may help the vet make a diagnosis.
A vet is trying to determine whether the intestine is being overactive or has ground to a halt. They are trying to work out whether the pain is being caused by an overactive intestine or due to a blockage. The outcome in both these cases is usually positive, provided the vet is in called quickly enough.
If the cause is a twisted bowel, the prognosis is poor unless the horse is well enough to undergo urgent abdominal surgery.
Colic caused by impaction usually results from undigested food passing through the stomach, where it collects in the caecum or large bowel. This is what results in the blockage.
Causes vary. The horse may have poor muscle tone in its gut, have defective teeth, or been eating poor quality roughage. If hard feed is a major part of its diet, a horse may develop an impaction if its meals are infrequent and large.
Sometimes, there may be a combination of causes, with a small site of parasitic infection weakening a section of bowel enough to cause an impaction as poorly digested food tries to pass.
The onset of a colic caused by impaction is usually slower, with the pain building up over 8 to 12 hours before it is clear to the owner.
The treatment will very much depend on the cause of colic diagnosed by the veterinarian. It may involve administering oil and a wetting agent via a stomach tube to assist in lubrication. The vet may also administer a worming agent. Painkillers will almost certainly be administered, which, aside from easing the horse’s discomfort, will allow it to eat. Owners will normally be encouraged to put the horse on green grass or provide lucerne hay. Depending upon the status of the intestine, the veterinarian may administer drugs to relax the bowel. They may even administer a drug to stimulate it, although a veterinarian would normally have to be very sure of his diagnosis and the cause of the colic before doing so.
Fluids may be given intravenously if the vet considers that the horse is in shock. The type and combinations of treatments will very much depend upon the cause diagnosed by the vet and the state of the animal.
Colic caused by a twisting of the bowel is the most serious. It is quite hard to diagnose, but pain is generally more pronounced and a horse will show no desire to eat or drink. In severe cases, the animal will pass no droppings at all. A horse is unlikely to survive beyond 24 hours.
Surgery is the only option to save the horse, provided it is strong enough to withstand an abdominal operation.
A twisted bowel will in many cases result from an already-colicky horse rolling, because a distended section of bowel is much more likely to twist than a relaxed portion. Owners of colicky horses are strongly advised to prevent an affected horse from rolling.
Giving a horse a large quantity of cold water while still hot after exercise is another cause of colic.
There are other types of colic, from spasmodic colic which arises in highly strung animals (the equivalent to a nervous stomach in a person) to enteritis colic, which may be caused by a bowel irritant, chemicals, or sand.
A vet will pursue the best course of treatment, depending upon their diagnosis. The most important thing is early intervention and diagnosis.
DISCLAIMER: Information in this report is of a general nature only and is not intended to replace the advice your veterinary surgeon.First published in February, 2006