Water Site Marking

Q. I have a question about my 11-year-old Warmblood mare. She's ridden six or seven times a week and lives in a medium-sized boarding stable in a 12-by-12-foot stall with straw bedding. She's been there for more than a year now.

Last June she started pooping in her automatic waterer. We would clean it out but find it again full of poop the next day. This became a daily occurrence until she was put out to pasture for six weeks.

In late August she came back to the stables, to her same stall. At first, all was fine. But in the past week she has picked up the habit of pooping in her waterer again! The stable keepers are sometimes cleaning it out twice a day. Today my mare had an episode of colic that the stable owner fears is related to not getting enough water.

Is there anything we can do? She actually seems quite attached to her water, as she has a very regular habit of dipping every other mouthful of hay into the water. I think the stable owner could be right that her colic is related to this, especially as she is so fond of this hay-wetting habit.

Do you have any suggestions? I actually wondered if there might be some sort of horse-sized water bottle (as are used in rabbit cages). Of course, if that did exist, my mare could no longer dip her hay in her water. But at least water would always be available to her.

Christa, via e-mail

A. To learn more about what might reduce or eliminate this behavior in your particular horse, I would recommend first moving your mare to a stall that does not have an automatic waterer. Provide water in one or more buckets--hung at different heights--that can be moved around to various locations every few days. This might help you determine one or more water bucket positions and heights that do not result in her defecating into the water. Just moving a bucket to another location or height can sometimes eliminate the behavior. Also try hanging more than one bucket at a time. To make it easy for her to dip her hay, you could place one water bucket near where her hay is fed. If there are no stalls available to you without automatic waterers, perhaps cover the waterer (you can usually find a horse-safe rubber feed tub that can be turned upside down to make a cap for the waterer).

While exploring these options, you can often learn a lot by setting a video camera on a tripod outside the stall and reviewing several hours of tape to see what your horse is doing.

If after a trial period she still soils her water no matter where or at what height you place the bucket, construct a bumper rail around the waterer or water bucket, such that your mare can reach her neck over the rail to drink, but she cannot back close enough to deposit feces into the water. Position the bucket and the rail high enough that she won't get a leg caught over it, and leave sufficient space between the rail and the waterer or bucket (8-10 inches should work well for most horses); that way, if she still backs up to the rail to defecate, the feces will fall to the floor between the rail and the waterer. You can create one of these rails by using a round post, a rubber butt bar, or a PVC pipe over heavy rope or chain--like a stall guard but fairly heavy.

Why horses exhibit this behavior in stalls or paddocks is not well-understood. Under natural conditions horses do display fecal marking behavior near their watering sites. This marking seems to be more frequent when water is in short supply. That's why providing additional sources of water in a stall can be helpful in reducing this behavior. I seem to hear about this behavior much more often with automatic water bowls, especially ones with fairly shallow reservoirs. Perhaps the shallow reservoir is perceived as a short supply, and that triggers the marking behavior. I don't think this question has been tested, but it would make a great master's thesis project.


About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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