Colic is one of the biggest equine killers, but new research is revealing vital clues about diagnosis and treatment. H&H reviews findings from the International Equine Colic Research Symposium, hosted by the British Equine Veterinary Association.

A block in the pipes
Large colon impaction — where a blockage within the gastrointestinal tract prevents the normal passage of gut contents — is a common cause of colic.

Until now, most studies on how large colon impaction cases present and are diagnosed and treated have been based at specialist referral hospitals. Researchers at the University of Nottingham, however, sought to find out more about the presentation and subsequent handling of such cases in “first opinion practice” — that is, by a visiting vet or an owner’s routine equine practice.

The researchers collected information on primary assessments over 12 months. More than 1,000 cases were recorded, 120 with large colon impaction diagnosed by positive findings on rectal examination. Half of these impaction cases were categorised as “simple” medical, a third as “complicated” and almost 10% as “critical”.

Some interesting trends emerged about the background of the affected horses and the possible causes.

Most cases occurred in winter, indicating a seasonal peak. More than half had had a recent change in management.

Almost half were not in ridden work, and one in eight had a recent or current musculoskeletal injury.

Large colon impactions typically presented with mild signs, while heart rate and gut sounds were the most useful parameters to distinguish between simple and critical cases at these primary assessments.

The findings of seasonal incidence and associated management factors are consistent with other studies.

Horses that need to be rested because of musculoskeletal injury or lameness, especially during the winter, are at particular risk of this type of colic. Preventive strategies, such as providing a laxative diet and some walking exercise, if possible, may reduce the risk.

Crib-biting and wind-sucking — a colic link?
Crib-biting and wind-sucking have been associated with an increased risk of colic in general, as well as with recurrence and specific forms of colic. A study by the University of Liverpool confirmed this belief, although researchers concluded that further study is needed to determine whether it will be possible to reduce the risk in horses showing these behaviours.

Owners and carers of 367 such horses participated in a questionnaire-based survey. One or more episodes of colic had been observed in one third of the horses. From the total of 672 reported episodes, 13 required surgical intervention.

Increased duration of ownership, longer periods of stabling in the autumn (from September to November), feeding haylage and crib-biting/wind-sucking behaviour associated with eating forage were all associated with an increased risk.

Driving up surgical standards
Researchers at the UK’s Bell Equine Veterinary Clinic and at Virginia Tech in the US have developed an online database of colic surgeries. The recorded information will be kept anonymous but the database will allow individual surgeons and hospitals to compare their results with those elsewhere. While such databases are common in human surgery, there are very few similar systems in the veterinary world.

Colic surgery is major and expensive. It is vital that surgeons should be adequately trained and experienced. Despite massive advances in the success rates over the past 40 years, a significant number of horses experience complications or die.

Being able to compare their own rates of complications with others is an important and valuable exercise.

For most owners there is no choice where their horse operated upon, and because the surgery is usually an emergency the closest hospital will generally be used. Making sure that the surgical team is working to a high standard, however, is an important consideration.

Could it be colic?
Despite the fact that colic is common and known to be a major concern, little is known about owners’ understanding and decision-making, even though this could assist vets in tailoring information with the aim of improving outcomes.

Researchers at the University of Liverpool used in-depth interviews and a cross-sectional questionnaire of 15 horse-owners to find out more.

Owners used three main management strategies: “wait and see”, meaning that they would watch the horse closely for further developments; “lay treatments”, which entailed walking the horse, for example; and “seek veterinary assistance”, the chosen option when professional help was needed.

In addition, a postal questionnaire gathered data from 673 horse-owners in the north-west.

It appeared that an owner’s previous experience shaped their interpretations and was critical in determining how they would deal with colic in their own horse.

This may mean that further education would aid owners in making appropriate decisions about when to seek urgent veterinary attention.

Counting the cost of surgery
Ever since the economic turmoil of 2008, vets have been concerned about the reduced willingness of owners to give permission for expensive medical or surgical procedures.

Surgeons at the University of North Carolina and Bell Equine Veterinary Clinic documented the numbers of colic referrals over the last 10 years. They also recorded horses undergoing surgery and euthanasia.

An interesting trend emerged at both practices. A decrease in the number of colic patients going to surgery was accompanied by an increase in euthanasia prior to or at the point of surgery.

Over the latter half of the study period, the cost of surgery rose by approximately 10% at both practices. This suggests that factors other than fee increases may have accounted for an increasing trend towards euthanasia of horses with surgical colic. Now that the economic outlook has improved, it is hoped that owners will be more inclined to allow their horses to undergo this life-saving surgery when it is required.

This article was first published in the 17 July 2014 issue of Horse & Hound magazine

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