Q: Why is snow not a suitable source of water for horses? Don't wild horses live on snow?
A: First of all, according to Chapter 346 in the MN Pet and Companion Animal Welfare Act, "equines must be provided with clean, potable water in sufficient quantity to satisfy the animal's needs or supplied by free choice". Snow or ice is not an adequate water source. There have been a few scientific studies that show some horses who are acclimated to winter weather conditions can receive their water requirements from snow.
However, there are serious health risks associated with snow consumption, including the adjustment period as horses learn to ingest snow, the actual water content of the snow, and total water intake. Some wild horses can receive their water needs from snow, but the risk of gastrointestinal tract problems, colic, and reduced feed intake is significant for domesticated horses. Relying on snow as the source of water for domesticated horse in Minnesota is illegal and not recommended.
By M. Hathaway, PhD & J.Wilson, DVM, University of Minnesota