You have probably seen this topic appear several times and in many places – with good reason. Colic is more common in winter (and fall), and the risk factors can be mitigated for the most part.
Impaction colic is always mentioned but risk of other types of colic can also increase. The factors include:
- Insufficient water intake. This dries the intestinal food contents as well as things that shouldn’t be there, like sand accumulations which become more physically irritating. Poor intake can be secondary to both insufficient water availability and the water being frozen or too cold. Contrary to what you may have heard, the horse will drink cold water. However, they drink less of it than warm water. Inadequate water is the major risk factor for impaction.
- Diet change. Transition from pasture to hay immediately slashes water intake considerably. It is also a diet change and should be done gradually to allow the organisms time to adapt. High fiber diets may be poorly tolerated by some horses, especially seniors, with development of diarrhea and/or colic.
- Inadequate salt. Many people think horses don’t need salt in the winter, or that they will always take as much as they need from a salt block. This is false. Suboptimal salt intake lowers water consumption. Adequate sodium from salt in the intestinal tract also enhances the absorption of many nutrients.
- Pica. Without grass to leisurely munch on all day, a bored horse that runs out of hay or becomes tired of it may sample wood, dirt or any type of bedding. This may contribute to colic.
- Inadequate exercise. This factor is often ignored but exercise is very important to intestinal motility. Even with light controlled exercise, horses going from pasture to stalled have drier feces and decreased motility despite drinking more water: https://www.ncbi.nlm.nih.gov/pubmed/?term=horse+exercise+intestine+motility . This is most pronounced for the first five days but the pattern will repeat any time there is a significant drop in movement – e.g. during a storm.
You can help combat all this by dividing an ounce of salt between feedings, or dissolve it and spray on hay (daily dose for average size horse). Make sure water is at least protected from freezing and keep it at a tepid warm temperature if possible. Feeding bran mash, soaked beet pulp or hay cubes/pellets and wet meals of any type will help get that critical water into the horse.
Feed hay from nets or feeders to slow intake. Keep hay close to the water source as horses will often eat for a while then drink when it is convenient to do that. Watch for excessive consumption of bedding or dirt.
Last but not least, make sure the horses get as much exercise as possible. Keep stall time to a minimum. Spread hay over a large area with several bags. Ride as much as possible and pony another horse or two along with you.
This is definitely more work than a quick visit to the barn to toss out hay and knock ice off water but lowering colic risk is well worth it.
Eleanor Kellon, VMD