Ask The Vet Live! Colic

In this first-of-its-kind, live question and answer session, horse owners were able to ask three veterinary specialists from The Ohio State University about colic, which is second only to old age as the leading cause of horse deaths each year. Below is a transcript from the original question and answer session on May 28, 2009.


Dr. Margaret Mudge--Dr. Mudge, VMD, Diplomate ACVS and ACVECC, is an Assistant Professor-Clinical in Equine Emergency and Critical Care and joined our faculty in February 2006. Dr. Mudge completed her equine surgery residency at the University of California-Davis and then entered into a fellowship in Emergency and Critical Care at OSU which she completed in 2005. Dr. Mudge, board-certified both in equine surgery and equine emergency and critical care, is responsible for the equine emergency service and therefore oversees a busy emergency clinic, especially adult horses and foals with gastrointestinal tract disease (colic). For more information, visit

Dr. Britta Leise--Dr. Leise, DVM, MS, Diplomate ACVS, is a Clinical Instructor in Equine Emergency Surgery and Critical Care. She came to OSU in August 2007 from Louisiana State University. Dr. Leise provides surgical and critical care services to the equine emergency service, including emergency colic surgery. She is completing her PhD studies investigating laminitis/founder, which is a common complication that occurs in ill and injured horses, especially those with inflammatory and ischemic gastrointestinal tract disease. For more information, please visit

Dr. Sam Hurcombe--Dr. Hurcombe, BVMS (DVM equiv.), MS, Diplomate ACVIM, is a Fellow in Equine Emergency and Critical Care. As such, he provides medical and emergency and critical care services for adult horses and foals. He has clinical and research interests in several areas including, medical and surgical management of colic, bacterial translocation in surgical colic, head trauma and foal sepsis/infection. For more information, please visit




Q: Can mild colic cause mild laminitis, or did the horse colic because of the mild laminitis?

Dr. Margaret Mudge: Certain types of colic and other gastrointestinal problems have been linked to laminitis, although the two do not always go hand-in-hand. More severe types of colic or diarrhea that can make the horse endotoxemic (toxic) are most frequently associated with development of laminitis. Laminitis does not typically cause signs of colic (such as flank-watching, pawing, rolling). However, pain from laminitis can cause the horse to lie down more frequently.

Q: We have one horse in our barn who seems to have colic off and on, and most of the others have never had a problem. What's up with that?

Dr. Britta Leise: Although horses can colic due to things in their environment - such as feed, feeding changes, pasture, deworming, exercise program etc. There is most likely some individual things that can cause colic. Some horses may have differences in there gastrointestinal motility that may make them more likely to get impactions. Some horses may have changes in their gastrointestinal flora that could make them more likely to be gassy. Horses that tend to colic more frequently may these or other problems that can be difficult to diagnosis and determine how to manage them. There are some diagnostic test that may help determine why this horse is colicky where others are fine - including things like gastroscopy for stomach ulcers, ultrasound of the abdomen, blood work to determine things like kidney and liver function, etc. If none of these things have been done they may be helpful in determining the cause.

Q: Can trauma from being kicked result in colic symptoms, and if so, what happens within body (only info I could find was bruised spleen may result in colic symptoms)? 7-yr old TB gelding kicked in mid-low area left abdomen, sounded like he was hit pretty solid. Within an hour, presented symptoms of elevated respiratory rate (~ 50), slightly elevated heart rate, temp 101.9, pawing, depression, gut sounds very reduced, no food interest.

Dr. Sam Hurcombe: Great question. Trauma to the abdomen, especially abdominal musculature absolutely could cause organ damage. Blunt trauma especially to the left side might cause splenic contusion (bruising and swelling), and may even cause a 'fracture' to some of these organs that have a high blood supply causing some bleeding in to the abdomen. This could absolutely cause signs of colic, either from the pain of the initial blow, bruising to the organs or even some blood loss in to the abdomen.

Q: I have a 10 year old Arabian mare that is overweight. She was overweight when I purchased her 3-1/2 years ago and stays that way. She gains weight just thinking about eating. I have put her on an exercise program which right now lasts from 45 min. - 1 hour and will increase as she loses weight and becomes fit. I also have been putting her in her run for about 4 hours a day where she has nothing but water. All our horses are pasture fed right now and the only way to keep her from eating is to confine her. When I turn her back out she runs out and eats like she is starving, which she isn�t. If I increase her confinement time, do I increase her chance for colic when I turn her back out? I didn't know if her frenzy to eat would increase her risk for colic. Thank you.

Dr. Britta Leise: Horses that gain weight by looking at grass can be difficult to manage. Anytime horses have changes in types of feed or amounts of feed they can be predisposed to colic. Some of these horses are more likely to have problems than others, though. One thing you could try is a grazing muzzle - that way she would not be as likely to eat as much when she is out.

Q: If I think my horse is colicking, what information should I give to my vet over the phone? Also, should I offer him water?

Dr. Margaret Mudge: The most helpful information for your veterinarian is the degree of pain (e.g. severe, violent rolling versus occasional flank-watching). Vital signs (heart rate, respiratory rate, and temperature) are also very helpful. In regards to the water, it is very difficult to make a horse drink when he doesn't want to, and you should NEVER force water via hose or syringe. It is usually a good idea to withhold any food when your horse is colicky, as many horses will continue to eat and add to an impaction or other gastrointestinal problem. It is generally OK to keep water available, although in some cases (as with upper intestinal obstructions) your veterinarian may withhold water as well.

Q: Do you tend to see more colic cases related to the season--like more in the spring and fewer in the summer?

Dr. Britta Leise: I would say yes--I think we tend to see gas related colics more often in spring-early summer when the grass is becoming quite lush and impaction type colics late fall and winter when they are eating more hay and tend to drink less water due to the cold.

Q: Have you ever heard of colic being caused by an allergic reaction in the small intestine?

Dr. Sam Hurcombe: "Food allergies" in horses have been postulated, but not proven. However, I would have to say that I do believe some horses have certain intolerances to some feeds, notably concentrates. I think the most common manifestation of these so called "allergic" responses is anterior enteritis, where horses accumulate alot of fluid in the first part of the small intestine and have a large volume of reflux. These cases do require intensive care. The other time you might see this allergic responses could be a quick change in feed type, causing a rapid shift in intestinal bacteria populations and colic.

Q: How do you tell if a young foal has colic?

Dr. Britta Leise: Foals actually will show the same signs for colic as adult horses, in that they will lay down, roll, and stretch out. Other things foals may do is lay upside down on there back and you may note them posturing as if to urinate or pass feces. Mild signs of colic may only be noted simply by the foal not nursing as frequently - these foals often are seen going to the mare's udder, but not really drinking.

Q: If I have a gray horse that has mild, intermittent colic, could that be a sign of internal melanomas? She has a big one under her tail.

Dr. Sam Hurcombe: Internal melanomatosis would be an exceedingly rare cause of colic in horses, even greys with quite severe cutaneous disease. There are no known reports of internal melanomatosis causing colic specifically. Occassionally perianal melanomas can cause rectal narrowing causing the passage of feces and gas difficult and this may lead to mild abdominal discomfort.

Q: Is there a way to reduce the gas in a horse's gut like Gas-X and other human medications do for humans?

Dr. Margaret Mudge: To my knowledge, no one has looked at Gas-x type products in horses. As with humans, diet and diet fluctuations are the most common cause of gas build-up in the intestines. Sudden diet changes, erratic feeding schedules, and high-carbohydrate feeds have all been associated with gas colic in horses.

Q: What�s the best formula to refeed a horse after colic surgery that involved bowel resection?

Dr. Sam Hurcombe: Refeeding practices after intestinal resection are highly variable and dependent on the site of resection (e.g. large intestine versus small intestine), the amount of bowel removed and the occurence of post operative complications (e.g. ileus and reflux, fever, bleeding etc).

In general, slow and steady wins the race when refeeding horses with resection to make sure the site of anastomosis is function and the horse does not develop colic again associated with the resection. For me, i like giving horses small amounts of feed such as equine senior, grass or softened hay, slowly.


Q: A mare at our farm had colic after foaling, and she ended up in surgery. Is that common? What happened?

Dr. Margaret Mudge: Post-foaling mares are a fairly high-risk group for surgical colic (usually colon displacement or colon torsion). This may be due to the "extra room" remaining after the foal is delivered, or due to alterations in intestinal motility after foaling.

Q: I've heard a lot about adhesions after colic surgery. What is that and how critical is it? What can be done about it?

Dr. Britta Leise: Adhesions are the main thing that concerns us with long term prognosis in our post-operative colic patients. Some horses develop mild adhesion after surgery and never have a problem with them where other may develop more numerous adhesion or even one adhesion that causes just the right problem. They are more likely to occur in young foals or horses that have small intestinal problems in surgery, although any horse can get them. It is estimated that 20-25% of horses with small intestinal problems develop adhesion post-operatively. Things to prevent adhesions are done in surgery and in the immediate post-operative period - such as using a sterile lube (we call belly jelly) which helps prevent the intestine from sticking to each other and using anti-inflammatory medications. If a horse has problems with adhesion, we can try to manage them medically (diet changes etc) but occasionally they may require an additional surgery to help remove them.

Q: My old, fat gelding seems to colic each spring when the grass is coming on strong. He�s never foundered, but the vet says it�s gas colic. He�s not worked much. How can I prevent this. I don�t have a barn, but I can lock him up in the run-in shed if I have to.

Dr. Margaret Mudge: Gas colic can be related to excessive carbohydrate intake, and spring grass is generally a very high-carb diet. You may be able to restrict intake of spring grass by allowing short periods of turn out (still feeding the hay that you fed over the winter) or by using a grazing muzzle.

Q: Can changes in weather cause colic? The old groom at my barn says that's true.

Dr. Sam Hurcombe: Changes in weather have been associated with colic there is even some scientific evidence to support this. Rapid shifts in weather can lead to changes in pasture composition, making them less or more digestible/fermentable and perhaps leading to increased gas production. This can be a cause of gas/spasmodic colic. Also, seasonal variation has been investigated for cases of anterior enteritis, and while there was no statistically definitive conclusion, there was a trend for horses to develop enteritis in the spring summer. Similarly, we also see more impaction type colics in the winter when horses don't drink as much and the pasture/forage quality is not as good.

Q: Do horses on dry lots have any special needs to prevent colic?

Dr. Britta Leise: Horses that are kept on dry lots may be at an increased risk of ingesting sand (particularly if you live in an area with sandy soil) or even gravel if that present in the lot as well. Therefore feeding horses off the ground (bucket or haynet) can be useful to prevent them from consuming sand, etc. Also since horses are meant to be grazing animals, they will tend to do better if they have hay present free choice or at least given more than 2 times a day. It will also be important that they have and drink plenty of fresh water as if they do not have access to grass (which is high in water content) they may be more likely to develop impactions if they are not drinking enough water.

Q: Does it make any difference in the treatment whether it is gas colic or impaction colic?

Dr. Sam Hurcombe: Great question. Gas colic and impaction colic often occur together, and so many times, they are treated similarly. With a primary gas colic, drugs such as flunixin (Banamine) and buscopan are very useful at relieving pain and spasm and often result in resolution. When gas is present because of an obstruction (e.g. impaction colic), treatment targeted at relieving the obstruction is often more important, such as cathartics (epsom salts, sodium sulfate, electrolytes), lubricants (mineral oil) and hydration control (enteral fluids through a tube and intravenous fluids). Most impaction colics of the large intestine should be able to be resolved using a combination of these treatments, however, in a smaller number, surgery is needed to completely resolve these, especially if the impaction is due to sand, an enterolith (rock) or gravel.

Q: When should you call the vet if you think your horse is colicking? Should you walk the horse until the vet arrives?

Dr. Margaret Mudge: If your horse does not 'snap out of it' within a few minutes, stops eating, has reduced or very dry manure, or seems at all distressed or bloated, you should call your vet. Walking seems to help some horses get through a mild gas colic, although it is okay to let your horse lie down if he is quiet and not rolling.

Q: Other than keeping a horse completely off grass and avoiding sudden feed changes, what are your recommendations to reduce the chance of gas colic?

Dr. Britta Leise: Sudden feed changes and feeding diets rich in carbohydrates can be associated with gas colics. The bacteria in the cecum help the horse digest the grain and hay - these bacteria can produce gas, so when there are sudden changes in feed or when these bacteria have a lot of carbohydrates to digest they then increase there gas production. If you have a horse that is likely to get gas colics then decrease the amount of carbohydrates (i.e. lots of sweet feed) may help in some of these cases.

Q: What's sand colic and how did my horse get it when he's on a grass field?

Dr. Margaret Mudge: Sand colic is most common in sandy area (logical, right?), such as Florida, California, and New Jersey, but we still see sand colics in horses here in Ohio. Sandy soil, riverbeds, and sand turn-out arenas are all possible sources for sand colic. Even on grass fields, some horses manage to ingest a large amount of soil.

Q: What's the association between colic and laminitis?

Dr. Sam Hurcombe: Colic and laminitis are often intimately linked unfortunately, however certain types are more likely to cause laminitis than others. Strangulating lesions of the intestine (especially large colon) result in a more severe inflammatory reaction and the feet are considered one of the main "shock" organs that become affected. When the bowel has been twisted, the inner lining (mucosa) becomes compromised and both bacteria and bacterial toxins can be absorbed in the blood stream. This results in an upregulation in systemic inflammation leading to altered blood flow etc to the feet.

Q: What do you think of having insurance for colic surgery?

Dr. Britta Leise: Hopefully if you have it you will never need it. However, insurance policies that cover colic can be useful if you need them. Colic surgery cost (with hospitialization etc) usually cost between $4,000-8,000 total. If you have your horse insured for mortality but not medical and your horse needs surgery to survive the insurance company usually will expect you to let the horse have surgery - So if you can not afford the surgery this could become an understandable problem. Most companies are reasonable to work with and will cover the surgical cost if it is recommend by the veterinarian.

You might also be interested in our online articles on colic.

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