Metabolic waste products such as Urea and Ammonium ions are removed from the circulation by the kidneys then eliminated from the body in solution in the urine. Urine passes from the kidneys to the bladder prior to periodic expulsion. Horse urine contains large amounts of mucus generated by the kidneys and bladder which may impart a cloudy appearance. Normal daily urine output is around 15 Liters or 30ml per kg bodyweight daily, but this will vary somewhat depending on diet, water intake and sweat output.
Brown discolouration of the urine is indicative of myoglobinuria caused by muscle damage and release of muscle breakdown products into the circulation subsequent to an episode of ‘’Tying Up’’. In severe cases the urine may be very dark, resembling coffee or Guinness beer.