COLIC

Colic is perhaps the most feared disease of horses. Most horse owners will have had or know of a horse that has died or required intensive treatment for colic. The term ‘colic’ simply describes abdominal or belly pain. There are many causes of this pain and it is likely that most horses will have an episode of colic at some point in their life. One of the problems with colic is that it can be difficult for an owner to distinguish in the early stages the difference between mild or potentially fatal colic. For this reason, it is important that all cases of abdominal pain in a horse be taken seriously from the very beginning.

SYMPTOMS

The signs of colic vary greatly between horses depending on their nature and the underlying cause of the pain. Signs that your horse may be in discomfort include:

• Depression, lack of appetite
• Sweating, pawing the ground
• Getting up and lying down repeatedly
• Kicking at the abdomen
• Trying to roll, sometimes violently
• Distended belly, looking larger than usual
• Turning to look at the belly/flank repeatedly
• Stretch out as if to urinate; may or may not pass faeces

CAUSES OF COLIC

There as so many different causes of colic in the horse. Some of the more common causes are listed below.

Gas Colic
Gas is a normal by-product of digestion and there is the potential for this gas to be temporarily trapped within the bowel, usually the large intestine, causing colic. In some cases, the increased gas is a result of access to a highly digestible food such as a sudden increase in grain or gorging unexpectedly. The gas stretches the intestine causing pain. So long as there is no obstruction or that the intestines do not twist on themselves, the gas will often pass and the colic resolves fairly easily.

Spasmodic Colic
This type of colic is a result of increased motility and spasms of the gut. Often owners can hear loud gurgling noises when standing by their horse’s side. These abnormal contractions cause the intestines to contract painfully and the bowel may also distend as normal digestive contents cannot pass freely through. The cause of spasmodic colic is often not found but could be anything from a diet change, medications, worming, stress, exercise, travel or a simple change in routine.

Worms
Worms can cause severe colic and potentially death in some cases. An excess worm burden can cause severe ulcerations, chronic irritation and in severe cases blood clots can form that block the blood supply to portions of the gut. Appropriately worming your horse will definitely help to prevent colic.

Impaction Colic
Impaction colic is a result of dehydrated food material, and occasionally plastic bags or baling twice, obstructing the bowel and preventing a normal passage. Pain in this case is from the blockage causing a build-up of fluid and gas in front of it. This stretching of the gut wall causes significant discomfort. Some horses can be treated with repeated drenches and fluid therapy however others may require surgery. Food impaction colic can be caused by high fibre feeds, limited access to water as well as poor dentition. If the horse is not chewing its food adequately, there will be a higher fibre content in the large bowel.

Sand Colic
Horses that are fed on the ground or kept in very sandy areas with poor quality pasture are at a high risk for sand accumulation in the large colon and subsequent colic. When large amounts of sand are ingested over time the gut does not work like it should. There are many commercial products available that contain high fibre levels that help to remove sand. Depending on the degree of sand accumulation, medical or surgical treatment may be required.

Twisted Bowel
This is potentially the most fatal type of colic a horse can develop. A twisted bowel occurs when a part of the intestine twists around itself, or another organ in the abdomen, causing the bowel to be strangled. When this happens, the blood supply to the bowel is cut off, irreparable damage occurs and that part of the bowel starts to die within the horse. Many toxins are released when the bowel dies and this can rapidly cause shock and death of the animal. This type of colic can only be treated by surgery. With any delay, the horse’s chance of survival are dramatically reduced.

DIAGNOSIS

When your Veterinarian is assessing a horse that is showing signs of colic, it is important to differentiate between medical (will get better without surgery) and surgical (will not get better without surgery) cases of colic. Many things are considered when making this decision such as response to pain relief and stomach drenching, amount of pain the horse is in, heart rate, respiratory rate, gum colour and quality of gut sounds. Other tests that may also be done include blood tests, a rectal examination, ultrasound and sampling of abdominal fluid.

TREATMENT OPTIONS

The vast majority of colic cases we see respond to medical treatment of pain relief, sedatives and stomach tubing in the field and resolve reasonably easily. When the horse does not respond to initial treatment then further therapy may be required such as blood tests, intravenous fluids and further stomach tubing. When
this is again not successful or the horse continues to deteriorate rapidly, immediate referral for surgery may be required.

Colic is not a static disease and it changes over time. This means that there is generally constant monitoring and a frequently changing treatment plan. We often cannot establish a treatment protocol at the beginning of treatment and expect to stick to it for the course of the disease except in extremely simple cases. Costs involved are extremely variable and could be anywhere from less than $1000 to more than $10,000, particularly if surgery is involved.

WHAT CAN I DO TO HELP PREVENT COLIC?

Many cases of colic occur despite the best care being given to the horse. Some things that can help reduce the risk are listed below.

• Regular dental care to ensure the horse is chewing their food adequately
• Regular worming every 8-12wks
• Provide fresh, clean water at all times and feed grain at a minimum
• Try to feed horses at the same time each day and avoid rapid changes in their diet
• Avoid feeding horses on the ground in sandy condition or where there is inadequate grass cover

COLIC & HENDRA VIRUS

Hendra virus is an emerging disease that has only been found in Australia. It can be transmitted from flying foxes to horses though any secretion such as contaminated urine, faeces or foetal fluids. Humans and other horses have become infected though close contact with infected horses. Despite Hendra being a rare disease, there is a sixty percent fatality rate for humans if the disease is contracted making it a big concern for horse owners and Veterinarians alike. The signs of Hendra virus are extremely variable in horses making it particularly difficult to diagnose in the field. Any neurological, respiratory or colic signs including a spike in temperature, could all be caused by Hendra virus infection.

For this reason, to protect ourselves and to protect you as a horse owner, we may take particular precautions in cases of colic in certain horses. If your horse appears to be presenting with any number of the above signs and has not been Hendra vaccinated, your vet may choose to wear Personal Protective Equipment (PPE) prior to examining your horse. They may also ask you to dress in PPE if they require assistance and a surcharge may be applied if the use of PPE is required. If your vet is particularly concerned, they may want to take samples to exclude Hendra virus as being the cause of the current illness. If this is the case, your vet will provide you with a clear action plan as to what will happen with your horse until test results return.

Your equine companion’s health and comfort is very important to us, however we also feel that the value of a human life is just as important. We strongly suggest that all horses are Hendra vaccinated as soon as possible to avoid the possibility of treatment being minimised due to the associated human risk. Please contact your local Veterinarian if you have any further questions or would like to book an appointment to get your horse vaccinated.

If you believe that your horse is showing any sign of colic it is important to seek Veterinary attention early on. Although colic is a feared illness, most cases will have a good outcome following appropriate treatment and care.

This information sheet is not intended as a substitute for a veterinary consultation. It is recommended that a consultation be arranged with a Veterinarian if you have any concerns with your animal’s health.