I am concerned that my Percheron mare is not drinking enough water, now that the seasons have changed. She has access to a salt block, but doesn’t use it that much in the colder months. Can I add anything to her water to make it a bit more appetizing? EO, Maine

Dear EO,

I just finished writing an article on impaction colic and agree that you are right in being concerned about the amount of water your mare is drinking. Fortunately, there are some things you can do to encourage her to drink more and hopefully prevent colic, dehydration and other problems.

First, instead of providing a salt block which some horses find uncomfortable to lick, provide her with loose salt or electrolytes. It’s easy to topdress her feed with 1 or 2 ounces of plain salt or salt (sodium and chloride) with other minerals such as calcium, magnesium and potassium. Electrolytes are safe because what the horse doesn’t need it just passes in the urine. They’re inexpensive insurance against a host of maladies. To learn how electrolytes work, visit one of my earlier blog entries.

Next, make sure she has access to fresh water from a clean bucket, tank or waterer of the appropriate temperature 24 hours a day, 7 days a week. What is the appropriate temperature? Dr. Sue McDonnell at the University of Pennsylvania has done some fascinating studies on the effect of drinking water temperature on the consumption of water by horses. Her team found that, while horses prefer cold water when given the choice between a bucket of warm water and a bucket of cold water, they will drink more warm water when that is the only choice. The water in their warm buckets ranged from 41 to 140ºF and averaged 66ºF. The water in the cold buckets was 32 to 33ºF.

Finally, some people like to get more water into their horses by feeding them a slurry. You can add warm water to hay cubes or pellets, pelleted grain, beet pulp or even hay to increase your horse’s water consumption. I’m not an advocate of the traditional bran mash anymore though, and not only because of the inverted Ca:P ratio. I’ve also learned that any laxative effect produced by bran mash is more likely due to an abrupt change in the diet causing digestive system upset than any true chemical or physical stool softening capabilities of bran.