Veterinary

More than a pain in the gut

Colic is a catch all term used to describe abdominal pain. The horse has a long gastrointestinal tract which is prone to a number of issues that can cause colic symptoms. In addition some other disorders can present with similar symptoms that can confuse the diagnosis. Endurance riding has the potential to put extra strain on all of the horse’s body systems and careful veterinary monitoring throughout competitions is essential. Outside the ride itself, colic can be linked with issues around transport or changes in diet linked with attending competitions away from home.

Colic can be caused by relatively mild disturbances to normal digestive functions, resulting in excessive gas or movement of the intestines. Blockages within the intestines can also result in abdominal pain. Blockages can result from impactions within the intestines or be caused when the bowel moves out of its normal position (a displacement). If the Tom Eaton-Evans qualified in 2000 from the Royal Veterinary College and is actively involved with endurance. He is the vet for the British Young Riders Endurance team and advises the Endurance GB Welfare Committee.

blood supply of the bowel also becomes compromised, such as by a severe twist of the intestines, this can affect the viability of the intestines leading to release of toxins into the bloodstream and a very sick horse.

Horses with colic can display a range of symptoms. These can vary between being quite subtle changes in behaviour that may only be picked up by experienced owners to very dramatic and uncontrollable rolling and sweating.

Veterinary assessment of colic Vets use a variety of tests as part of a clinical examination to assess a colic patient. The clinical examination would typically consist of taking the horse’s heart rate, breathing rate and temperature. The mucous membranes, capillary refill time and skin tent are assessed for signs of dehydration and toxaemia. The gut sounds are listened to with a stethoscope over four quadrants of the abdomen. Many aspects of this examination are shared with the veterinary assessment performed at an endurance ride. Further tests are then performed as appropriate. A rectal examination allows the vet to carefully feel the abdominal contents which may allow impactions or displacements to be identified. A tube can be passed into the horse’s stomach which can identify if excessive gas or fluid is present. Ultrasound examination

of the horse’s abdomen can provide further information about gut position and activity beyond what can be felt during the rectal examination. By assessing the degree of pain alongside the clinical parameters and observations a tentative diagnosis can be made and appropriate treatment initiated.

Management of colic Colic is usually regarded as a veterinary emergency. Horses in pain can be unpredictable and dangerous so horses with colic should always be approached with caution whilst waiting for the vet. If there is any concern over your own health and safety it may be best to leave the horse until further help arrives. However, if safe to do so, it can be useful for the horse to be walked as this can help encourage normal gut motility and in milder cases of colic distract the horse from the pain. It is important to be aware that an uncomfortable horse can throw itself to the ground suddenly and therefore it is safest to walk the horse in a paddock or in a school.

Once the vet has arrived and made their initial assessment, they will decide on a treatment plan based on their findings. An antispasmodic injection (Buscopan) is useful for cases of excessive gas or hypermotility of the intestines. This can be combined with an injection of painkiller depending on the horse’s level of discomfort. Impactions are likely to require the administration of fluids or laxatives by stomach tube along with some pain relief. Some horses with impactions may require multiple visits from the vet before they clear, or may require intravenous fluids and further monitoring in a hospital environment. Mild bowel displacements can resolve with antispasmodics and pain relief, but may require more intensive monitoring and intravenous fluids in a veterinary hospital depending on their response and progress. More severe displacements and twists affecting the blood supply to the bowel will need surgery. It is important to monitor the response to treatment and have the horse reassessed if progress is unsatisfactory.

Colic at Endurance rides Although thankfully rare, colics are occasionally seen at endurance rides. Listening to gut sounds is a part of the examination of the horse’s metabolic condition with reduced or absent intestinal noises being a warning sign of exhaustion. This represents a reduction in intestinal motility, which may result in ‘ileus’ or stasis of the intestines which can be intensely painful as the stomach and intestines fill with gas. Intravenous fluids are the treatment of choice as this helps counteract the dehydration in exhausted horses and improves blood flow to the intestines thus improving motility. Great care must be taken with using painkillers in endurance horses as dehydration increases the risks of side effects which could result in permanent kidney damage. The passing of a stomach tube to release gas build up and the use of sedatives can be useful to manage painful horses whilst administering fluids. Horses with ileus would be expected to become more comfortable after an hour or two of rapid intravenous fluid administration, with progressive improvement of metabolic indicators (heart rate, mucous membrane colour, capillary refill time and gut sounds) during this period. Horses may also develop displacements or twists during endurance competitions so a horse that does not respond to treatment in this time frame would be best moved to a hospital setting for further monitoring and evaluation that cannot be performed at a ride,

Some other conditions of endurance horses can show similar symptoms to colic. Horses that have ‘tied up’ can paw the ground and sweat, whilst horses that are overheating can kick at their belly and throw themselves to the ground. Careful observation and monitoring can usually differentiate between these conditions (for example the stiff gait in a tied up horse would be unusual in a true colic), although starting intravenous fluid therapy in any severely metabolically compromised endurance horse is usually beneficial.

Prevention of colic in endurance horses Maintaining the consistency of the horse’s diet in the lead up to a competition will help to minimise the risks of colic. Taking forage from home to a competition will help to minimise disruption to the essential bacteria in the horse’s gastrointestinal tract. Probiotic

supplements can also help in this regard. Endurance horses often have plentiful access to grazing at home and thought needs to be given as to how to best manage these horses whilst travelling to a competition where even if corralling is available the grass may be very different to what the horse is used to. Finally horses who are prone to stress or lack of appetite at competition should be assessed for stomach ulcers as this can be managed by appropriate medication.

Signs of colic

Dullness Lack of appetite Restlessness Quivering/curling of upper lip Grimacing Flank watching Stretching Attempting to urinate frequently Pawing Kicking at belly Crouching Sweating Rolling