The question comes up from time to time if municipal water supplies are OK for horses. The concern is generally related to the added chlorine or added fluoride in the water. The water is treated with chlorine to minimize risk of bacterial contamination, and the fluoride is added to improve human dental health.
The chloride may change the aroma and taste of the water. Taking horses to facilities with chlorinated water can sometimes reduce water consumption. Reduced water consumption may impair performance and may also increase the risk of impaction colic. Horses do adjust to the difference in taste and aroma over time, but this may take a few days. It is routine in many barns to flavor the water with something like wintergreen or peppermint at home, then flavor the water at the new location or while traveling to match the home water.
- NOTE: Do NOT use soft drinks that contain caffeine or any material containing caffeine as these can trigger positive drug tests!
The fluoride levels in municipal water supplies are normally at about 0.5 to 1.0 mg/liter of water. The maximum dietary allowance for horses is about 4-8 mg/liter (Source: Mineral Levels in Animal Health-Diagnostic Data, Second Edition, R. Puls), so the level in municipal water is well below any levels associated with heath risk for horses.
Municipal water should be OK for horses. When changing water sources, consumption should be monitored to make certain horses continue to consume adequate water with flavoring the water being an option when traveling. As always, salt should be available free choice.