Colic doesn’t follow a calendar. Virtually any horse can be stricken with gut pain at any time of year. That said, there are certain types of colic that are more likely to occur in winter than at other times of year. A veterinarian called out to see a colicky horse on a frigid day in January is going to expect to find a certain scenario that she wouldn’t for the same type of call in June.
The colics most associated with the cold weather months are impaction- related. When ingested feed stops moving through the horse’s gut efficiently, the material can accumulate and form a blockage. Feed and gas then back up behind the blockage, causing distention of the intestine and associated pain. Impactions are often found in an area called the “pelvic flexure,” a hairpin turn the large colon makes back on itself, but can also occur in other locations.
Thankfully, impactions are typically easy to diagnose---many can be confirmed during rectal palpations---and treatment is often straightforward. A dose of painkillers, possibly a sedative, along with hydration usually gets things moving again. In more severe cases, hospitalization so that intravenous fluids can be administered might be necessary, but even those horses tend to recover quickly. Of course, it’s easier on everyone if colic doesn’t occur in the first place.
In that spirit, I’m going to share the four management tips that will contribute the most to protecting your horse from winter colic or, at the very least, recognizing it early when it’s easier to treat. These aren’t things you haven’t heard before, but it pays to refresh your memory and resolve as we head into winter.
1. Keep your horse hydrated.
Any discussion of winter colic needs to start with hydration. Impactions are more likely to form with dry feed, and horses, for a number of reasons, tend to drink less in the winter. As simple as it may seem, frozen water is the most common reason I see for horses becoming dehydrated in the winter.
A water bucket can freeze within six to 12 hours, so if you’ve filled it in the early evening, your horse very well may spend some part of the night without water. If you chip away the ice and refill the bucket in the morning, the water may freeze again by the afternoon. A horse needs to drink from eight to 10 gallons of water a day, and that can be difficult if all he has is ice half the time.
So your first line of defense against winter colic is to make sure your horse’s water source never freezes. There are many methods to accomplish this.
A variety of products, ranging from insulated buckets to tank heaters, can help keep water flowing. Keep in mind, however, that if an electrical component for one of these products shorts out, your horse will be zapped each time he goes for a drink. If he isn’t drinking from a bucket or trough equipped with a heating element, offer him water in a “low-tech” plain bucket. If he drinks, there may be something wrong in the heated water supply.
A second reason horses can become dehydrated in winter has to do with water temperature. A study compared how much horses drank when offered ambient, near-freezing water compared to hot water. The researchers found that the study horses drank 41 percent more water when offered continuously heated water. The horses drank 38 percent more when offered buckets filled with hot water twice daily compared to ambient, near-freezing water. They seem to prefer to drink warm water when it’s cold outside. Few of us have the luxury of hot running water in the barn, but an electric teakettle can come in handy. Filling a bucket with hot water has the added benefit of slowing the freezing process. Ideally, horses have access to water all day, but the most important time is in the three hours after feeding.
Another strategy for getting water into a horse during winter is feeding mashes. Bran is, of course, the traditional mash base, but I prefer to make more nutritionally balanced mashes---senior feeds work particularly well. The notion that it’s the bran preventing colic is outdated thinking; it’s the water keeping him hydrated that is helpful. So just add some warm water to your horse’s regular feed to make a slurry and serve it right away. Most horses love mashes. You can also add a teaspoon of salt to encourage the horse to drink more, just like we would after eating a bag of salty chips.
2. Provide as much turn out as possible.
It’s a well-established fact that a horse who is kept in a stall for most of the day is more likely to colic than one who is turned out. Pasture living keeps a horse’s gut moving. Not only is the physical activity of walking around beneficial, but continual grazing is what he was designed for. That’s why we strive for frequent, small meals to mimic the natural, healthiest eating patterns of a horse at pasture.
And while confined horses are at higher risk of colic, those who were recently moved to a stall are even more likely to develop digestive upset. A recent British study showed that a horse’s gut motility slows significantly in the first five days after a move from pasture living to stall confinement. This, combined with less water in their diet as they shift from pasture to dry forage, adds up to an increased risk of colic.
All of this becomes crucial during the winter, because that’s the season when horses are more likely to be confined, due to either inclement weather or convenience for riders. Horses may have to be pulled off pasture abruptly if a snowstorm hits, leading to the dramatic change in management that immediately increases their chances of colic.
The best way to mitigate this risk is to leave your horse turned out as much as possible. A horse with a thick winter coat or an appropriate blanket can live outside comfortably even in single-digit temperatures. A run-in shed or even a thick stand of trees is adequate shelter in a snowstorm.
If full-time turnout doesn’t work for you in winter, keep your horse outdoors as many hours as are feasible. It’s also helpful to set up your pasture in a way that encourages your horse to walk as much as he might while grazing in spring or summer---spread out hay piles and put the water trough far from the gate so he’ll have to move around. If pasture turnout simply isn’t an option for a period of time, look for other ways to help your horse exercise. A few hours of liberty in an indoor arena are better than an entire day spent in a stall, as is hand-walking up and down the aisle.
3. Feed plenty of forage.
When pasture dies back in winter, hay replaces grass as the foundation of a horse’s diet. A horse on adequate pasture full-time will be continuously digesting water-rich grass, ideal for preventing colic. In winter, however, meals of dry hay are more common and can be associated with colic. Not only is drier forage more likely to create intestinal blockages, but the gut slows in the hours spent waiting for hay to be served twice a day.
Forage also figures in another common wintertime challenge: Horses will burn more calories in cold weather to stay warm and, in some cases, may begin to drop weight as a result. The natural instinct is to increase a horse’s feed to counteract the weight loss. But increasing grain instead of forage is a mistake. Not only are you missing the opportunity to provide more gut-healthy hay, but the additional concentrates can lead to gas colic as the high-calorie feed ferments in the gut.
The best wintertime feeding practices include frequent, primarily hay-based meals. Using a slow feeder to make hay available to your horse 24-7 is a great idea. If your horse is dropping weight and he already has free-choice forage and no underlying health issues, consult with your veterinarian about the best way to add more calories to his diet. Rather than doubling up on grain, switching to more energy-dense hay might be a safer choice. In addition, many complete feeds that can be used to increase caloric intake are not as rich as straight corn or other grains. Remember to always make the transition to a new feed over several days.
4. Be vigilant when storms roll in.
There are plenty of anecdotes about horses colicking when the weather changes dramatically. Talk to enough people and you’ll hear stories of horses ---maybe even several in one barn---that colicked just as a large nor’easter snowstorm blew into the area.
And as a veterinarian I see it, too. When we know a cold front is coming through, causing a dramatic change in the weather, we prepare ourselves for a rash of colic calls. However, studies looking to conclusively link weather change to colic haven’t found a correlation. This could be because of the difficulty in quantifying weather patterns. Or extremely localized conditions may complicate analysis: What’s happening on your farm atmospherically may not be the case a few miles down the road.
So we can’t say with certainty that weather changes cause colic, much less explain why, but it is a phenomenon that is observable enough to take it into consideration when thinking about winter colic.
With that in mind, keep one eye on the forecast and be extra vigilant when a storm front is moving in. If there is an increased risk of colic when the weather changes, you don’t want to pile on with other risk factors. That means making sure your horse has water, forage and some room to move around as soon as is feasible. Also, try to avoid making changes to his routine and management when the weather changes. When the storm arrives, check your horses regularly and watch closely for signs of colic. A colicky horse in winter may not be especially sweaty, but be on the lookout for restlessness, dry and/or scant manure, lying down more than usual and “flank gazing” as he looks back at his painful sides.
This article first appeared in EQUUS issue #447, December 2014.