12/11/2025
COLD WEATHER COLIC
Brian S. Burks, DVM
Diplomate, ABVP
Board Certified in Equine Practice
Winter is back, and snow is on the ground (at least in some areas). There are several things to consider for your horse when it comes to winter.
The number one cause of colic during cold weather is lack of fresh, unfrozen water. Most horses consume 25 liters (12 gallons) of water daily. Horses not getting enough water, for whatever reason, are at risk for impaction (and other) colic. Even if the water is not frozen, some horses may not like super-cold beverages; water is best at 45-65 F for most horses. A heated water bucket could be used, but these are potential fire hazards. If you are going to use heated water buckets, ensure that the horse cannot get to any portion of the electric cord, so that it cannot be chewed upon, and that it is plugged into an outlet with a ground fault interrupter (GFI). Also, check the electric in the entire barn for frayed wires, ensure that the circuit breakers are functional, and that the correct amount of current is being pulled from the electric source.
If the water is too cold for your horse, and you are not using heated water buckets, consider adding warm water to make the bucket contain tepid water. Hot water can can freeze faster than cold water (mpemba effect). There are also bucket cozies to fit around the water bucket and help prevent freezing. Consider adding appropriate amounts of electrolytes to the water; every brand is different, but Peak Performance has electrolytes without fillers such as sugar. Salt may be added to grain or hay to help encourage drinking. Snow will not compensate for inadequate water sources, as it is largely comprised of air, thus not providing the same volume of water.
A second factor to consider is parasitism. This can sometimes occur in well dewormed horses. Small strongyles, or Cyathostomes, overwinter in the intestinal wall of the horse. When the larval forms detect that the outside temperatures are no longer warm- they like 70-800 F- they will, sometimes en mass, pe*****te the bowel wall where they have arrested development, or hibernation, and this massive entrance, causes intestinal inflammation. Clinical signs range from weight loss, to partial anorexia, to unrelenting pain, depending upon the amount of infestation.
There is no good way to test for larval cyathostomiasis. Since they are larval forms, there is no egg production to be detected upon f***l examination. It is not practical to take biopsies of the colon, but they can be obtained from the duodenum via gastroscopy and the re**um. If the samples detect an eosinophilic enteritis, this is supportive, with appropriate clinical signs of larval cyathostomiasis. Abdominal ultrasonography may also be supportive. The bowel wall may have thickening, and there may be hyperechoic (bright white) foci present within the bowel wall.
It is important to recognize that most dewormers do not affect the encysted larval forms. There are a couple of ways to treat this condition, one of which in tube deworming for three days with high doses of fenbendazole. Moxidectin gets at least some of the larval forms, but not all of them.
Gastric ulceration may occur due to the stress of being kept inside rather than being turned out, as in the summer months. You may choose medication as prevention, or simply continue to turn out, except in extreme weather. Horses that are used to being turned out in cold handle the weather without any problem. Turn out also keeps the horse moving, which helps keep the GIT moving, preventing colic. Standing in a stall reduces intestinal motility. Remember that wet blankets will make horses colder than no blanket at all, although wet hair coats do not function normally. When on turn out, adequate shelter should be provided to allow them to get out of the wind, rain, and snow.
Providing adequate forage is essential for proper digestive function. This will also provide more internal heat to keep your horse warm. Horses were designed as continuous grazing animals, and providing free access to hay will not only keep them warm, but ensure adequate gastrointestinal function, helping to prevent colic from impaction and gastric ulceration. High-fiber forage, however, can make movement through the intestinal tract more difficult, especially when coupled with decreased water intake.
The cold affects many things, including humans that do not wish to be out in sub-freezing temperatures. By spending a few more minutes, however, you may help ensure your horse gets through the winter with minimal issues.
Dr. Brian Burks is the owner/veterinarian at Fox Run Equine Center, a 24-hour medical-surgical center near Pittsburgh, Pennsylvania. He is board certified by the American Board of Veterinary Practitioners (Equine Practice). This certifies him as an expert in all categories of equine practice.
Fox Run Equine Center
www.foxrunequine.com
(724) 727-3481
