Colic is a term used to describe all types of abdominal pain in horses. It can affect horses of all ages and types, and can vary from a mild bout of discomfort that resolves itself to something more serious that requires medical management, or most dramatically a serious abdominal crisis requiring surgery. Every year hundred of horses lose their lives to colic, with some high profile top competition horses among them.
Most colic cases are successfully cured medically, but between 5-10% will require emergency colic surgery. It is difficult to know which colic case fits into which category, as in the early stages the clinical signs are the same. Therefore it is vital that a vet is called promptly so they can give expert advice and start appropriate treatment as quickly as possible. Any colic that requires surgical intervention has a much better chance of success if surgery happens as soon as possible.
Types of colic in horses
There are many different types of colic that horses can suffer from. The list below is not exhaustive, but covers the most common examples.
- Spasmodic colic : Also known as gas colic, pain is caused due to a build up of gas in the horse’s gut due to excess fermentation within the intestines or a decreased ability to move gas through it. It is commonly caused by a change of diet, a lack of roughage or parasites. The clinical signs are generally mild and respond well to pain relief and spasmolytic medications.
- Impaction colic : This is when a blockage occurs in the intestine. It typically responds well to medical treatment in the form of pain relief, fluids and laxatives, but some cases will require surgery. If left untreated, severe impaction colic can be fatal.
- Sand Colic : Most typically seen in horses kept on sandy pastures, especially when there is limited grazing available. The horse ingests sand (and dirt) which accumulates in the gut. It can lead to an impaction or it can irritate the lining of the bowel, causing diarrhoea. The weight and abrasion of the sand or dirt causes the bowel wall to become inflamed and can in severe cases, leads to peritonitis.
- Twisted Gut : There are various parts of the horse’s gastrointestinal tract that may twist upon itself, leading to an interruption in blood supply to that section. A twisted gut is extremely painful for the horse and requires emergency surgery.
- Tumours and previous damage to the gut wall caused by parasites can also result in colic.
Causes of colic
The causes of colic are numerous, but generally they are related to the anatomy and the microflora of the horse’s gastrointestinal tract. Some more common causes of colic include:
- High grain based diets/Low forage diets
- Mouldy/Tainted feed
- Abrupt change in feed
- Parasite infestation : a significant number of colic cases are as a result of, or exacerbated by, worms
- Lack of water consumption leading to impaction colics
- Sand ingestion
- Long term use of NSAIDS (non-steroidal anti-inflammatory drugs)
- Stress
- Dental problems
Signs of Colic
In addition to general changes in behaviour a horse with colic may exhibit some or all of the following signs:
- Pawing
- Rolling
- Bloating
- Sweating
- Distress
- Uneasiness
- Loss of interest in food and water
- Peculiar postures (sitting, stretching)
- Absence of gut sounds
Treatment
It is vital that a vet is called promptly so they can give expert advice and start appropriate treatment as quickly as possible. To give the proper treatment for colic, it is important to determine the cause, so that it can be corrected. The severity of the signs of colic is not necessarily indicative of the severity of the colic, and sometimes it is difficult to determine the exact cause and therefore the correct treatment. For these reasons make sure to have a vet evaluate your horse as soon as possible. Many cases of colic can be treated successfully with medication, while others involving severe impactions or twists may require immediate surgery.
Fortunately most cases (around 90%) of colic seen by vets in practice can be treated with pain relief (analgesia) and other medical treatments without needing to refer cases to hospital facilities such as ours.
These medical interventions can include:
- Pain Killers : Short acting to aid examination or longer acting to control pain during natural recovery. Care has to be taken to ensure that colic symptoms are not masked
- Fluids: Given orally to help clear ingesta (feed) that has become stuck (impacted) within the large intestine
- Motility modifiers: These are drugs that can alleviate cramping or spasms of the gut where this is the cause of pain
- Gentle exercise: Under strict veterinary supervision, exercise can alleviate some causes of colic, such as colonic displacements
- Gastrointestinal reflux: Horses are unable to vomit, so intestinal blockage could cause a back up of fluid in the stomach causing rupture (which is fatal in horses). This finding usually indicates more serious forms of colic requiring possible surgery
- Surgery: In around 10% of colic cases, surgery is needed to save the horse’s life. If surgery is needed to treat colic, it is critical that this is performed as early as possible to maximise horses chances of survival (and often can reduce the costs of aftercare too).
While you are waiting for your vet, you should:
- Observe your horse and monitor vital signs as well as passing of any feces. Remove access to feed. If there is a blockage, any feed intake will only intensify the problem
- Let the horse rest as much as possible. It is not necessary to walk the horse unless the horse is rolling and endangering himself or people
- Do not administer any medication without the direction of the attending vet. Pain medication may mask the colic symptoms and complicate diagnosis and treatment.
Why is colic so common in horses?
Horses evolved on a different diet from the one they’re expected to eat today. The manner in which horses eat and the time they spend eating has changed considerably – even a horse living at grass eats a different diet from his ancestors. Unfortunately for the domesticated horse, his intestines have not evolved to meet these changes and, as a consequence, he is susceptible to digestive upset. A horse’s digestion involves fermentation of which a by-product is gas, which can easily distend the gut causing problems. Horses cannot vomit to get rid of toxins, or indigestible food. The gut has a large absorptive area (needed because the animal is a herbivore) which leaves the horse susceptible to toxins being absorbed quickly. Also, natural feeding habits mean that nature designed the horse to be on the move, grazing on the way. This is known as “trickle feeding” whereby the horse eats large quantities of low-energy food throughout the day, typically spending 16 hours a day feeding. Today’s management of horses often indicates two feeds a day of hard feed, rationed hay and stabling for eight hours without exercise or food. This is obviously very different to the life the horse was designed to lead. This change from the natural and ideal situation means that horses can react to any added stress on their lifestyle, which is often the cause of colic.
Prevention
Once you figure out the cause and have treated the colic, some of the preventative measures are self-explanatory. For example, if an abrupt change in diet caused a problem, make sure to make dietary changes gradually in the future.
Some other preventative measures include:
- A constant supply of fresh water
- Small and frequent feeds of concentrates if necessary. Only use hard feed as a supplement to the grazing and high fibre food available to the horse
- Plan a diet consisting of high fibre content, using hay or other high fibre equivalent feeds. A ratio of at least 60 per cent hay or equivalent
- Ensure the feed is of good quality and is not mouldy, and has no hidden hazards such as baling twine/plastic
- Set a regular exercise programme, ensuring that the horse is fit for the work needed. Do not suddenly overexert your horse
- Have a post-exercise cooling off period
- Make any changes to exercise or feed slowly
- Allow as much turn out in a paddock as possible
- Have regular dental checks as poorly chewed food increases the risk of a blockage in the intestine
- Do not overgraze pasture
- Ration lush spring grass, treating it as a change of diet to the horse
- Wherever possible, avoid your horse grazing heavily sanded pasture
- Ensure the worm control programme is kept up to date as recommended by your vet
- Have a regular daily routine and make changes gradually.
