azoturia is a condition in horses characterized by poor muscle metabolism. the problem appears to be a build-up of excess lactic acid in the muscles, resulting in a severe and rapid muscle cramping ("tying-up"). the most severe cases are accompanied by the release of myoglobin into the urine, a phenomenon known as "black water disease" because of the dark pigmentation of said urine.

other signs include profuse sweating, high temperature, lameness/stiffness (especially in the hindquarters), and shorter stride during exercise.

if this occurs, it is advised to stop exercising the horse immediately, give it a rest, and contact a veterinarian. anti-inflammatory drugs, sedatives, muscle relaxants and IV fluid therapy may come in handy, but rest is most important.

azoturia occurs for a lot of reasons, mainly because a horse has been given the "day off" but still fed a high-energy diet. the next day, that horse is sure to get muscle cramps because of the lowered pH from the excess grain (see monday morning disease). the horse could also not be getting enough electrolyte supplementation; this is particularly a concern in hot weather. a final cause seems to be related to estrus in mares, which appears to have some sort of hormonal effect upon muscle metabolism.

there are several precautions you can take to insure this doesn't happen to any of your horses:

  • decrease the energy and protein content of the feed on non-workdays
  • exercise the horse regularly; don't make a habit of skipping workdays
  • make sure your horsie is getting enough electrolytes in hotter weather
  • potassium salt and baking soda can be used as a supplement in the feed to buffer the pH from the lactic acid