Emily Steele, DVM

Colic simply means "pain in the abdomen" or in other words, a belly ache.  In the horse, a belly ache can be caused by everything from excess gas to a life-threatening intestinal twist or blockage.  One of the most common questions I am asked when treating a colicking horse is "How could I have prevented this?"  While not all colics can be prevented, there are many steps you can take to decrease the chance of colic and improve the overall health of your horse. 

It is likely that for as long as people have owned horses, parasites have been a major source of colic.  There are several different species of intestinal parasite, all of which use the horse's internal organs during a large part of their life cycle.  Through their migration tracts and feeding, these worms can cause havoc in the gastrointestinal system.  Intestinal parasites can cause colic by irritation of the gut wall, cutting off blood supply to sections of the intestinal tract, and can even cause blockage of the tract with their sheer numbers.  Parasites are also very adept at evolving and have the ability to become resistant to dewormers if exposed to the same one month after month.  Research now shows that a larval form of one parasite is able to form a cyst in the gut wall and stay there for up to three years.  These larvae are not susceptible to typical dewormers and must be treated with a deworming program targeted specifically at the larvae.  It is best to consult your veterinarian for the deworming program best suited to your area and farm.  In general, we recommend that our clients deworm every 6-8 weeks with rotating dewormers and then perform regular fecal examinations to ensure their deworming program is sufficient. 

Another cause of colic in horses is improper dental care.  Horses have teeth that continually erupt throughout their life and are worn down by constant grinding of their food.  Grinding all food into small particles is necessary for normal digestion of food in the horse.  In the wild, the constant grinding of rough grasses keeps their teeth in normal wear.  However, horses in captivity are often fed much richer, softer feed and very commonly develop sharp edges on their teeth.  These "points", as they are commonly called, inhibit normal grinding motion and can actually cause pain in your horse's mouth by rubbing on their gums.  In addition, some horses are born with abnormal dental conformation and have increased difficulty grinding their food.  Improper grinding causes the horse to swallow larger, coarser food particles.  These food particles can go on to cause irritation and blockage in the intestine, which in turn, leads to colic.  We recommend dental exams 1-2 times per year to ensure that your horse's teeth are in good condition. 

Sand is also a very common culprit in equine colic.  It is ingested when horses graze in sandy areas or eat off the ground.  As it passes through the gastrointestinal tract, sand can be extremely irritating and in some cases, can cause a blockage, also known as an impaction.  Once formed, sand impactions can be very difficult to pass and often require surgery.  A good way to check for sand in your horse's diet is to place manure in a clear, plastic bag with water.  If excess sand is present, it will quickly sink to the bottom of the bag.  Horses can be given psyllium supplements to help remove sand and prevent colic.  The supplement Sand Relief is sold at our practice.  However, in the fight against sand, it is equally important to prevent sand ingestion by feeding horses off the ground or in tubs. 

An easy but often forgotten technique to prevent colic in horses is to make sure they are consuming enough water.  To properly digest and pass manure, your horse needs proper hydration.  From 40⁰ below in the winter to 105⁰ F in the summer, all horses need clean, fresh water available all the time.   Forgetting to clean or fill the water tank or not checking the water heater in the winter can lead to dehydration and colic in your horse.  Water tanks can also become electrified if they are touching an electric fence or if you have an electric fence that is not properly grounded.  If you are concerned about your horse's hydration status, an easy test you can do is the pinch-test.  When pinching the skin on a normal horse's neck, the skin will snap back into place.  A dehydrated animal's skin will take several seconds to go back into place. 

What you feed your horse can also help decrease their chances of colic.  The horse's gastrointestinal system is designed to ingest forage continually and slowly digest throughout the day.  When horses are fed only a couple large meals a day, their gastrointestinal tracts have difficulty coping with a large quantity of material and then a subsequent lack of food.  In addition, feeds high in starch such as corn and molasses can upset the gastrointestinal tract.  The inflammation and gas caused by such feeding practices can greatly increase a horse's risk of colic.  Feeding frequent, small meals with low starch feeds and/or free-choice hay are a great way to promote a healthy gastrointestinal tract.  Some feed companies are now developing feeds designed to augment a forage–based diet rather than to replace forage with grain, which is an excellent step in working toward improved, safer diets for our horses. 

Finally, horses are very sensitive to change.  A dramatic change in training, feeding, or environment can be enough stress to cause colic in the horse.  Therefore, it is important to make all changes as gradually as possible.  During these times of stress it is especially important to monitor your horses feed and water intake and overall behavior.  If you do notice any change in behavior or hydration, one of the most important steps you can take to prevent a more serious colic is to call your veterinarian.  By treating early and appropriately, many potentially serious colics can be avoided.