COLIC

The term colic refers to abdominal pain in the horse.  There are many causes of colic and many different symptoms, this is because the horses digestive system is complicated and due to the length (which can range between 30 to 40 meters long) and variation in tubular diameters many different problems can occur.  Not all of the digestive system is attached to the abdominal wall and so some of the intestine can move freely in the abdominal cavity.  If your horse has colic it is important for the veterinary surgeon to visit as soon as possible to establish which kind of colic your horse has and treat it accordingly. 

SIGNS OF COLIC

Colic symptoms can be broken down into three stages depending on how painful your horse is feeling.  Even during the low grade stage you should speak to your vet for advice. 

Low Grade Pain

• Lack of interest in feed
• Curling the top lip
• Turning to look at flanks
• Mild pawing of ground

 

Mild Colic

• As above plus:
• More intense pawing of the ground
• Urge to roll or lying down for long periods of time
• Restlessness
• Frequently standing as if wanting to urinate

 

Severe Colic

• Severe sweating
• Continuous rolling or inability to stand
• Increased breathing with flared nostrils and heave line on abdomen
• No evidence of droppings being passed
• Grazes or swelling around eyes from injury whilst rolling

 

Types of Colic

There are many different types of colic and different causes, we have listed the most common types.  With all of the types that we have listed it is important not to try and diagnose it yourself, it may appear to be a ‘simple’ colic which will pass but often colic can become a surgical case within a very short period of time.

• Spasmodic

Occurs when intestine contractions increase or go into abnormal spasms which are very painful.  The symptoms usually last for a couple of hours and gradually wear off.  It can be a result of a mild gas build up which increases gut sounds.  This type of colic is usually treated with muscle relaxants and mild painkillers given by your vet.

• Sand Impaction

This is when sand gathers in the intestine from grazing on very short pasture or sandy areas.  The sand becomes heavy and sits in the pelvic flexure, right dorsal colon and the caecum of the large intestines.  The weight and abrasion of the sand causes inflammation of the intestinal wall, and so passing of faecal matter can become very slow, the irritation can cause severe diarrhea.  In most cases the sand may be removed using laxative diets and use of the herb psyllium, which collects the sand in the intestine and allows it to be excreted naturally. Unfortunately, in some cases surgery is required to remove the sand.

• Impaction

This form of colic is very common and occurs when the large intestine becomes blocked by food material causing constipation.  It is a fairly common type of colic and often occurs following a period of stabling in the winter months or when horse have eaten a high proportion of fibre (e.g straw). This type of colic is usuall;y treated medically with pain killers and laxatives and surgery is usually unnecessary.   

• Displacement/Torsion

Displacement is when a section of intestine moves to an abnormal position within the abdominal cavity.  A torsion (twisted gut) occurs when the intestine twists. This causes the intestine to totally block. This type of colic produces more severe pain which only partially resolves with pain killers and usually requires surgery to correct the problem.

• Intussusception

This type of colic refers to when a segment of intestine telescopes into an adjacent segment. The intestine quickly becomes trapped and obstructed as it starts to become inflamed. Intusscusceptions are common in younger animals at 3-12 months and are also seen in adults due to tapeworm infections.

 

 

• Gastic Distension/rupture

If a horse gorges on grain or food that can swell in the stomach (ie sugar beet), there is a possibility that the stomach could burst as horses do not have the ability to vomit.  Stomach pain is often severe in the horse and can rapidly be fatal if the stomach ruptures.

• Gastric ulcers

Gastric ulceration (stomach ulcers) in the horse are very common in racehorses in training and competition animals receiving high levels of feeding. Clinical signs of gastric ulcers can be vague; such as weight loss and ill thift to mild colic around feeding time and tooth grinding. A diagnosis is made by passing a long flexible endoscope into the stomach (gastroscopy) to examine the stomach lining. Treatment is readily available using medical treatment with anti-ulcer drugs such as omeprazole and cimietidine.

The image on the left shows an abnormal stomach lining as ulcers are present.

The image on the right is how stomach lining should be.

 

• Strangulating Lipoma

This is a fatty benign tumor that is round in shape and is attached to the mesentery via a long narrow cord.  They vary in size from 5cm in diameter to bigger than an orange.  They may entwine around the intestines causing a strangulating obstruction. The entwined intestine is often severely damaged and requires removal under general anaesthesia.

This lipoma has looped around the intestine causing stragulation and the intestine to turn black.

 

• False Colic

The term ‘false colic’ refers to any other type of abdominal pain which is not related to the intestine, such as bladder pain or uterin pain. Mild colic is common in pregnant mares as the foal moves around close to the end of pregnancy. Kidney pain and testicular pain may also occur and the horse will display signs of colic. 

How does my horse digest food?

Food enters the mouth and is mixed with saliva.  It then travels down the oesophagus.

The oesophagus is on average 1.2 – 1.5 meters in length.  Its purpose is to take food to the stomach.  The stomach has a volume of 15 litres.  The food is then broken down, which can take between 15 min and 24 hrs in the stomach.  The food then passes through the pyloric sphincter to the small intestines.  The small intestine hangs from a curtain like membrane called mesentery, this is attached to one point in the middle of the abdomen under the spine.  It looks like a gathered net with the small intestine running along the bottom of it. The small intestines are the major organ for digestion and are 15-21 meters (50-70 ft) in length.   There are three sections to the small intestine, the duodenum – 1 meter in length, supplies bile from the liver, digests sugars, starches and breaks down proteins to amino acids.  The second stage is the jejunum which is around 20 meters in length.  This is where absorption takes place through the walls of the intestine to the blood stream and cells.  The third section is the ileum, around 50 – 70cm in length and is a much thicker muscular part of the small intestine. It takes on average 30 - 60 minutes for the food to reach this stage.  The remaining liquid and roughage then reaches the large intestine which fills a large part of the abdomen. This organ is ‘tethered’ to the body wall at only two points (at the beginning and at the end).  It is then very neatly arranged in a double U formation on top of the other.  This again is broken down into three sections. Firstly the food matter reaches the caecum which is around 1.2 meters (4 ft) in length and has a volume of 26 – 30 litres. Vitamins and fatty acids are absorbed through the intestinal wall but little protein.  Microbes will break down the fibrous matter such as hay and grass.  The next stage is the large colon.  This is 3 – 3.7 meters (10 – 12 ft) in length and can hold upto 76 litres of fluid.  This is where nearly all of the nutrients are absorbed.  It is also when fluid is absorbed before reaching the small colon.  The small colon is 3 – 3.7metres in length and this is where faecal ball formation occurs. It then travels into the rectum where the undigestable matter is held until it is passed through the anus and expelled.  This whole process can take upto 50 hours.

What should I do when my horse has colic?

• Take away any food or water that is available to your horse
• Make sure your horse is in an environment where if they decide to roll injury is less likely
• Do not give your horse any drugs.  The vet needs to make a diagnosis without any symptoms being masked
• And ALWAYS call your vet, they may give advice or wish to visit.  Even if the colic appears mild it could be a serious case, so getting medical treatment as soon as possible is vital for your horses care

Does every type of colic need surgery to rectify the illness?

No, on the vets first visit they will be listening to gut sounds, monitoring how much pain the horse is in and often will complete a rectal examination.  This allows them to feel for any abnormalities with the intestines.  Depending on their findings they may give pain relief, a muscle relaxant, and advise you to monitor the horse for an hour and then give the vet a ring with an update.  The majority of these cases will then subside and the vet will advise you on management for the next 24-48 hours.  In more severe cases the horse may need to be brought into the hospital where one of our nurses will monitor them during the night.  During this time additional pain relief or fluids will be given.  In extreme conditions the horse will need surgery to rectify the cause of the colic.

How can I reduce the risk of my horse getting colic?

• Regularly worm your horse.
• Avoid eating over rich diets.
• Keep grain and pulp feeds locked away out of reach of the horse.
• If feeding horses outside do not feed from the ground in sandy areas as if large volumes of sand are eaten this can cause colic.
• If changing the horses’ diet, this should be done gradually over 2-3 days