Colic is a broad veterinary term used to describe any form of abdominal pain.
There are a range of different causes of colic; most of these are gastrointestinal in nature but occasionally colic can be the result of urinary and reproductive problems.
Signs of colic
Knowing and recognising signs of colic is very important for all horse owners, as it will allow you to notice even subtle changes in your horse’s behaviour and allow us to attend to your horse as soon as possible.
Colic signs may include:
- Pawing at the ground
- Flank watching
- Kicking or biting at the belly
- Repeated lying down
- Rolling
- Holding head in unusual position
- Repeated curling back of upper lip
- Sweating
- Stretching out as if to urinate
- Dog sitting
- Lying on back
- Depression
- Inappetence
Types of colic
Idiopathic / Spasmodic
This is certainly the most common type of colic, and equates to the majority of colics we treat in our practice. Spasmodic colic occurs when the bowel is contracting in an abnormal manner creating painful spasms and somewhat of an “over-active” gastrointestinal tract. Spasmodic colics usually respond very well to anti-spasmodic drugs along with other therapeutic treatment. Idiopathic is a veterinary term for “unknown origin”. Despite the best veterinary investigation there are still plenty of instances where we are not sure about the exact cause of the abdominal pain. The good news however, is that the vast majority of these colics respond to on-farm medical treatment.
Impactions
This term describes when the bowel, usually the large intestine, is blocked by a firm mass of food. This is a fairly common type of colic and can often resolved on farm with administration of fluids and/or liquid paraffin via a stomach tube. Occasionally, larger and more persistent impactions may require surgical intervention.
COLIC MYTH: While paraffin oil may have some mild laxative-type effects it is mainly used as a marker to be detected in the manure at the other end, indicating gut transit.
Displacements, strangulations and torsions
Displacements occur when one section of the bowel moves to an abnormal location within the abdomen. Strangulating colics occur when the blood supply to a piece of gut gets cut off. Torsions occur when the bowel twists on itself cutting off the blood supply. The horse’s gastrointestinal system is unusual (and badly designed!) due to the fact that large sections of the bowel are either suspended in place by loose lengths of tissue (eg the small intestine) or completely unattached to the body wall (eg the large intestine). Both these factors predispose the horse to displacements and torsions. Strangulations, displacements and torsions are intestinal accidents that are uncommon but are very serious in nature. Some displacements can be treated by starving and medical therapy but severe displacements and all strangulations and torsions require immediate surgery to correct the problem. The early stages of strangulating or displacement colics often present in a very similar manner to the more common, less life-threatening forms of colic – the major reason to take all colic episodes seriously and call the vet at the earliest signs of abdominal pain.
What to do if your horse has colic
1. Call your vet – colic is a true veterinary emergency and time is of the essence
2. Place your horse in a small yard or a well bedded stable to allow for easy and close observation
3. Remove all food from the stable until the veterinarian arrives
4. If your horse is rolling violently, try walking them or keeping them standing. Violently rolling horses often hurt themselves, so trying to prevent self-trauma is helpful, but don’t put yourself in danger!
COLIC MYTH: Rolling won't cause your horse to "twist its gut". Keeping your horse walking or standing is recommended to avoid self trauma!
The veterinary colic exam
The colic examination is a complex evaluation of a multitude of interacting factors with many differing variables.
The following is a brief overview of some of the parameters that your vet will assess and some of the procedures they may perform.
Heart rate
An elevated heart rate is usually a good indicator of pain and can often be an indicator of severity of colic. A normal resting heart rate is around 34-40 beats per minute.
Mucous membranes and capillary refill time
Your vet will look at the colour and moistness of your horse’s gums and will then asses the ‘capillary refill time’ by pressing on the gums to blanch them and seeing how long it takes for colour to return. Mucous membrane colour, moistness and capillary refill time help to assess your horse’s hydration status and are good indicators of blood perfusion. Normal gums should be salmon pink, moist with a capillary refill time of less than 2 seconds.
Gut sounds
By listening to the gut sounds through a stethoscope your veterinarian can get a good indication of how much activity is occurring inside the abdomen. Your vet will usually listen to the upper left, lower left, upper right and lower right sections of the abdomen and determine what sort of gut sounds are present. Gut sounds are broadly grouped into 4 categories: increased, normal, decreased, and absent.
Rectal examination
The rectal exam is a vital part of the colic diagnostic process, as it allows the vet to feel what is occurring inside the abdomen. Most horses will require sedation to perform this examination if a crush is not available. The vet will be able to assess if there are any major abnormalities present such as an impaction, or if there is a distended loop of bowel due to a twist.
Passing a nasogastric (stomach) tube
Passing a tube up your horse’s nose and down into its stomach is both diagnostic and therapeutic. Your vet is first of all looking for what is termed “gastric reflux”. Gastric reflux occurs when there is a blockage in the bowel (usually the small intestine) that causes the build-up of fluid in front of it. Unlike other species the horse can’t vomit and the stomach can rupture due to build-up of fluid.
Ultrasound exam
An abdominal ultrasound can give your vet an indication of gut motillity and the presence of increased or abnormal free fluid in the abdomen. This can be readily done with a portable ultrasound machine.
Treatment
After assessing all the different factors involved in your horse’s colic, your vet will decide on the appropriate course of treatment. This may include administration of fluids/electrolytes down a nasogastric tube if an impaction is suspected.
Pain relief is one of the cornerstones of colic therapy and your vet will decide what drug and how much is appropriate. Once pain relieving drugs are given, we want to see a good response and the disappearance of all colic signs.
If colic signs recur, it is vital that you contact your vet as a horse that is still painful despite pain relieving drugs may need to be referred to a hospital for further investigation and possible surgery.
Colic surgery
One of the main things that a first opinion vet treating colic in the field needs to determine is whether the horse can be managed medically or whether it is likely to require surgery. There are many different indications for surgery and your veterinarian will assess them during the colic investigation.
It must be remembered that the vast majority of colics do not require surgery and respond well to on-farm treatment, but if your vet does feel that your horse needs surgery, or at least requires further investigation at a referral hospital, time is of the essence.
The decision to take your horse to surgery can often be very difficult and unfortunately due to the nature of colic, a rapid decision is required. Many factors are involved in making this decision such as severity of the problem, likelihood of a success, expense etc., but your vet is well trained and will be able to help you make the right decision for the horse.