There is one word that strikes fear in a horse owner’s heart: colic. It is the most common cause of death in horses, and any horse is at risk. Defined as anything that causes abdominal pain, the cause of colic may be anywhere from mild and self-limiting to severe and life-threatening.
What is Colic
While anything that causes abdominal pain can manifest as signs of colic, most types of colic are caused by issues with the gastrointestinal system. The horse digestive system has evolved to be very sensitive to changes in environment and feeding.
Some unique anatomical features that make it susceptible to problems include variations in diameter of the large colon and limited attachment of the intestine to the body wall. These features predispose the horse to impaction colics (blockage with ingested material) or torsions (twisting of the intestine).
- Not eating
- Not passing as much or any manure
- Looking at its side (flank watching)
- Stretching out
- Tightening or curling of upper lip
- Pawing intermittently
- Laying down more than usual
- Laying down, getting back up constantly
- Severe sweating
- Continuous, frantic pawing
- Becoming cast (stuck in a position unable to rise without assistance) in the stall
Mild signs of colic include not finishing a meal, a decrease in manure production, flank-watching, or repeatedly stretching out. The most common type is called spasmodic colic, where the gut becomes gas-distended and painfully contracts.
Moderate signs of colic include pawing, laying down quietly, or exhibiting light muscle tremors. Horses exhibiting mild signs of colic for more than one to two hours that do not resolve by walking the horse or any moderate signs should be seen by a veterinarian. In any case, your veterinarian should be advised as soon as possible if the horse is exhibiting signs of colic.
Examples of diseases that cause moderate signs of colic are obstructions found within the intestine, called impactions. Displacements are another common type of colic that usually first result in signs of moderate colic. Spasmodic colic can sometimes lead to these displacements. The horse large colon has loose attachments to the body wall, meaning it can migrate to abnormal areas as it becomes gas distended, resulting in pain, spasms, and dysmotility.
Severe colic signs include circling and rolling, sometimes to the point of horses hurting themselves or becoming stuck against stall walls (becoming cast). These horses should be seen by a veterinarian immediately or taken to an equine hospital if a veterinarian is not readily available.
Examples of colic that cause serious pain are very bad displacements or strangulating disease. The latter is the most serious type of colic and is when part of the intestine twists around itself (torsion or volvulus) and cuts off blood supply. Immediate diagnosis and surgical intervention are critical for successful treatment of twisted intestine.
Causes of gastrointestinal colic can be broken down into obstructions, strangulations, and functional problems that cause decreased motility.
- Displacements of the large colon
- Large colon volvulus
- Pedunculated lipoma (a benign fatty tumor) strangulating a segment of small intestines
- Incarcerations of a piece of bowel (epiploic foramen entrapment, scrotal hernias)
- Functional problems
- Spasmodic colic
- Abnormal motility of the small intestines (enteritis or duodenitis proximal jejunitis)
- Infectious (Salmonella, Clostridium)
- Inflammatory Bowel Disease
A horse owner should call their veterinarian immediately if they suspect colic. While waiting, your veterinarian may recommend you give your horse a medication called Banamine (flunixin meglumine). Ask your veterinarian during your horse’s annual exam if you should keep a dose at your barn for emergency situations. This drug is similar to the non-steroidal anti-inflammatory ibuprofen, so it is important to not overdose your horse or give it too frequently.
Your veterinarian may have you walk your horse until they arrive if your horse’s colic signs are not so severe as to risk your safety.
Your veterinarian will perform a physical exam by looking at your horse’s gums, checking their heart rate, respiratory rate, and temperature, and listening for intestinal sounds. Your horse may be sedated to make the exam more comfortable and safe.
A key part of diagnosis and treatment in a colic exam is called “passing a nasogastric tube.” Because a horse’s anatomy doesn’t allow them to vomit, a downstream obstruction in the digestive tract can cause the stomach to overfill, resulting in painful distention. The specialized tube is passed from your horse’s nostril to its stomach and is used to medically treat the horse with a large bolus of mineral oil to help loosen the impaction.
Most colicky horses will also be palpated rectally by your veterinarian and has been an important veterinary diagnostic method for hundreds of years. With a good horse handler and judicious use of sedation, a rectal examination is a relatively safe procedure.
Other diagnostics that may be recommended by your veterinarian include bloodwork, testing for parasites, and ultrasound. Some causes of colic can be chronic or ongoing. One of the most common types of this is stomach ulcers in horses, which can be diagnosed by passing a camera (gastroscope) into the stomach.
Many colic cases can be treated on the farm. After the physical exam, your veterinarian will probably ask you to remove your horse’s grain and hay and call them with any worsening signs. They’ll also probably want to recheck your horse the next day to ensure everything is fully back to normal.
If your horse doesn’t respond to treatment on the farm, it may need to be taken to a hospital. Make sure to have a plan in place to transport your horse. While some horses that go to a veterinary hospital need surgery, many of them only need intravenous fluids and supportive care. Hospitals can also run advanced diagnostics to further evaluate the cause of colic.
If colic is very severe, especially those that involve twisted intestines, your horse will need surgery to survive. This can be a scary time for any owner. It is important to consider your financial limitations and options before having to make this emotional decision. An equine surgeon can give you information on costs and complications.
How to Prevent Colic
Some types of colic can’t be prevented, but the risk of many common types can be managed. Feeding horses quality hay and changing grain or new types of feed slowly are keys to success. Supplying ample fresh water and elevating feed if the horse lives in a sandy area are also important to prevent sand colic. Colic is quite common, but having a plan of what to do if your horse colics may save its life.
Tinker, Mary K., et al. Prospective study of equine colic incidence and mortality. Equine veterinary journal 29.6 (1997): 448-453. doi.org/10.1111/j.2042-3306.1997.tb03157.x
Colic in Horses. VCA Animal Hospitals.
Overview of Colic in Horses. Merck Veterinary Manual.
Equine Emergency Procedures. Merck Veterinary Manual.