Colic: why does it kill? *H&H VIP*

  • Colic is a problem that has frustrated horse owners and vets for centuries, and the frustration continues to this day.

    The term refers to abdominal pain, usually arising from the stomach or intestines. However, since the gastrointestinal tract of the horse is about 100ft long, there are various locations within it that can be affected and numerous different diseases that can result in signs of colic. Unfortunately, the word “colic” is often associated with serious, life-threatening diseases, whereas, in truth, the majority of cases (around 90%) are caused by relatively benign and easily treated diseases.

    Since colic is a sign of pain, it is not a true diagnosis. Determining the underlying cause of colic can be challenging and, in many cases of benign colic, the precise diagnosis will never be established.

    This is similar to the stomachaches that people commonly suffer from — the cause of most of these is unknown but they resolve spontaneously with little or no treatment.

    Notwithstanding the fact that most horses showing colic will recover with simple treatments, the condition is still a common cause of death. Why are so many horses still losing their lives to colic, despite many decades of research into the subject and substantial advances in veterinary medicine, surgery, anaesthesia and intensive care that we have experienced in the past three decades?

    Here’s the twist

    There are many potential reasons for this.

    “Strangulating” diseases of the intestines often cause the most serious colics. An example is a twist, or “volvulus”, which could occur in the large colon, or entrapment of intestine in internal hernias and anatomical spaces — such as entrapment of small intestine in a small cavity called the epiploic foramen. Another possibility is strangulation of the intestine by a pedunculated lipoma, which is a fatty growth that develops on a stalk and then wraps itself around the intestine.

    Strangulation means that the blood supply to an area of the intestine is cut off; as a result, the affected part of the intestine dies and bacterial endotoxins (poisons) that are normally confined within the intestines can enter the bloodstream through the damaged intestinal wall. These toxins result in septic shock and circulatory failure, which will ultimately lead to death.

    The whole process from the initial development of the strangulation to advanced shock and death may occur in only a matter of hours. Thus, time is of the essence. If the horse with a strangulation of the intestine is to be saved, the diagnosis and treatment — in this case, surgery — must be carried out swiftly.

    Because the signs and symptoms of colic are non-specific, recognising which horses have a serious, life-threatening colic and which will recover with simple medical treatment is not always clear-cut.

    In general, horses with severe, unrelenting pain are more likely to have a serious surgical disease — whereas those with mild or intermittent colic are more likely to have a disease that can be managed medically. This is not always the case, however.

    Warning signs

    To maximise the chances of recovery from a serious bout of colic, the horse needs to be diagnosed and treated quickly. Ideally, you will identify early signs of colic, which may initially be subtle and include reduced production of droppings, restlessness, decreased appetite and dullness, before the more overt signs of abdominal pain such as pawing, flank-watching, rolling and sweating become apparent.

    Unfortunately, one of the most common reasons why some horses still die from colic is that diagnosis or treatment is delayed. This is either because the problem is not identified straight away — maybe the horse develops colic during the night, for example, and isn’t found until the morning — or because the decision or ability to take the horse to surgery is delayed for some other reason, such as transport problems.

    Early examination by a vet is vital. Having a plan in place before the horse develops colic is always helpful, so that the decision about how to manage him in the case of illness is already made.

    For horses that require colic surgery, the overall success rate is generally around 70-80% — that is, this percentage of horses are discharged home following the surgery. Whether an individual horse will survive depends on numerous factors, such as the duration of colic prior to surgery, the precise condition that the horse is suffering from and whether post-operative complications occur.

    Colic surgery is major and expensive. It is important that the team that performs the surgery and aftercare is well-trained and experienced. Most horses will need to stay in the hospital for five to 10 days afterwards, with an additional period of around eight weeks of box rest back at home to allow the abdominal wound to heal.

    Complications can occur, such as “ileus” — the inability of the intestines to start functioning again — and wound infections. In most cases, such complications usually resolve in time. Sometimes, however, the complications can be life-threatening in their own right.

    Shakespeare’s adage “Better three hours too soon than a minute too late” is a good one to remember when dealing with colic. If you are in any doubt about whether your horse requires referral for colic surgery or not, it is always better to transport the horse to hospital sooner rather than later. Everyone will be delighted if it turns out that surgery is not required, but delay could well lead to an unhappy outcome.

    Ref Horse & Hound; 28 December 2017