If you’ve been around horses long enough, you’re bound to have experienced the picky drinker. Horses that are selective in their water consumption can not only be frustrating for owners, but could also be a danger to themselves, as dehydration can be a serious problem. A team of Canadian researchers, however, recently revealed that horses tend to prefer water with neutral pH levels rather than low pH levels, meaning your picky drinker’s problem could be due to acidic water’s sour taste.

"Although work has been done on the palatability by horses of specific flavors, such as peppermint and banana, there is little research available on the basic tastes," explained Katrina Merkies, PhD, a researcher at the University of Guelph’s Kemptville Campus in Ontario. Merkies’ graduate student, Jaime Carson, presented the results of a recent related study at the 2011 Equine Science Society Symposium, held May 31-June 3 in Murfreesboro, Tenn.

Distilled or pure water has a pH of 7 out of 14 on the pH scale (which measures how acidic, neutral, or basic substances are). For comparison, acidic water has a pH lower than 7 and has a more sour taste. Lemon juice’s pH, for example, is 2 out of 14.

To determine if horses showed a strong distaste for acidic water, Merkies used 12 horses (aged 2 to 18 years) in a "random block" study design. Each horse received each treatment (water at a pH of 5, a pH of 3.6, or a pH of 2.9, adjusted by adding citric acid to the water) for four days with a two-day washout period between each different pH. Horses were also provided with "control water" that had a pH of 7.5 during each test period. Water buckets were replenished as needed, and researchers measured the amount of each type of water the horse consumed daily