Red snow

If you notice red spots in the snow this time of year, while alarming, are a normal oxidative process that occurs after the urine has been voided from your horse.  Normal horse urine sometimes turns red or brown after standing for a while in the snow.  This is due to the presence of oxidizing agents termed "pyrocatechines" in the urine.  It is rare for a horse to pass blood in the urine and when present is almost always accompanied by some abnormal void behavior.  Frequent urination and straining are the most common indications of a disease in the lower urinary tract.