Often unpredictable and frequently not preventable, colic is a continual concern for all horse owners and is a frightening concept when it is your horse that is colicking. In the horse, "colic" officially refers to any type of abdominal pain. Luckily, most types of colic respond well to medical therapy on the farm. This article will cover some of the basic types of colic, what your veterinarian is doing when dealing with a colic episode, standard treatments for colic and some of the potential complications. Also, we have now identified a few risk factors that increase the likelihood of colic. Being able to avoid these factors may help you decrease the risk of colic in your horse.
Gastrointestinal
Anatomy
Horses have an intestinal tract that is adapted to digest hays and grasses. The first part of the gut is similar to that in people: food travels down the esophagus, is exposed to acid in the stomach, then digestion and absorption begin in the small intestine. The remainder of the gut is greatly elongated and specialized to process the cellulose in hays. The cecum (resembles the appendix in people) and colon (large intestine) are very large and take up most of the space in the abdomen. Because of its length, the colon is folded on itself and loops around, somewhat like a folded extension cord or ribbon. The extra length gives the horse more time to remove nutrients from the hay. These portions of the gut also contain microorganisms that help digest the hays.
When to call
ADVERTISEMENT
the veterinarianWhen a horse is painful from colic, he will often look at his side and bite or kick at his flank or belly. More severe cases will lie down and/or roll. In some cases, manure production will be decreased or absent, or the manure will be dry or covered with mucus. Frequently horses may not eat all their grain or hay. Often they will improve when walked. If you know the colic is of recent onset and appears mild, you can try walking the horse and seeing if he improves without veterinary assistance. If it has been several hours since the horse was last observed (duration of colic signs unknown) or if the colic is more severe and unresponsive to walking, a veterinarian should examine the horse as soon as possible. Owners can learn to take pulses and to check the horse's gums for signs of dehydration or toxicity. If the horse's heart rate is more than 45 to 50 beats per minute or if the gums are tacky, have a prolonged refill time or are off color, the horse may be dehydrated or toxic and needs immediate attention.
Treatment for colicIn most instances, your veterinarian will diagnose a probable impaction or gas colic. Treatment usually involves controlling the horse's pain with analgesics, softening the impaction with mineral oil or other laxatives, and encouraging motility by having you walk the horse. She will likely recommend that you not feed the horse hay or grain until he passes manure and the colic resolves. If an impaction is present, more food would just add to the problem. (However, grass does not contain much fiber and the act of grazing may also help stimulate bowel motility.)
Most cases will respond to this type of treatment within a few hours. A few horses will need additional fluids for rehydration (oral or intravenously) or may need to be reexamined. If the colic is more severe, requires intensive treatment, or does not resolve with on-farm treatment, the veterinarian may recommend you take the horse to an equine hospital equipped for abdominal surgery and intensive care.
Prevention of colicHorses are prone to colic and many types of colic cannot be prevented. However, there are some relatively simple steps that can be taken to ensure that your horse is at the lowest possible risk for colic. These factors have been found to alter the risk of colic in epidemiological studies.
- Always have fresh, clean water available - horses on pasture without a water trough available are at increased risk of colic even if without water for only one to two hours (the risk is increased 10 times if they are more than 6 years of age). If the water is not fresh they may not drink enough. Closely monitor automatic waterers and water sources in winter. Stop to let trailered horses drink and/or pretreat them with mineral oil before starting a long trip.
- Allow pasture turnout - horses that had access to two to three different pastures during the previous month had lower colic risk than those without pasture access.
- Avoid feeding on the ground in sandy areas - horses may ingest enough sand to cause motility problems and gut irritation; feed them off the ground to decrease sand ingestion.
- Feed grain and pelleted feeds only as required. Colic risk is increased 70 percent for each pound increase in whole grain corn.
- Watch horses carefully following changes in exercise, stabling, or diet and avoid changes whenever possible - horses with a change within the last two weeks were significantly more likely to colic; farms with more than four changes in feed in the year had three times the incidence of colic than farms with less than four changes.
- Watch broodmares closely in the two months following foaling and watch any animals that have been ill or have colicked before - all are at increased risk of colic.
- Have your horse's teeth floated every six months - this ensures good mastication of hay and may help prevent impactions of coarse feed stuff.
- Control parasites - horses on a daily wormer or regularly dewormed with ivermectin or a similar product have been found less likely to colic. Be careful when deworming foals: the dead parasites may actually block the intestine. Work with your veterinarian to customize a deworming program for your horses. Deworm all horses at a barn simultaneously and control manure levels on pastures.
Above all, be a proactive owner. If your horse is being placed at unnecessary risk for colic, try to adjust the situation. If your horse does colic, appropriate and timely care may make a great deal of difference in the outcome. Do not hesitate to call your veterinarian if you are concerned about your horse and if you are unsure about the examination or treatment, ask questions.
