POP QUIZ ANSWER
Relax. If your horse is otherwise healthy and is acting normally, this ranks as zero on the panic scale. The red spots that you see are a result of the urine reacting with the cold snow. Proteins in the urine, called pyrocatechines, oxidize in low temperatures, which produces colors ranging from a light pink to red, orange or brown. The same thing can occur when a sample of urine is refrigerated.