New name, Old problem
What used to be known as Monday Morning Disease and was incorrectly called azoturia, should be Performance Horse Syndrome, or more correctly "too much dietary calcium."
But today everyone calls it "tying up."
The name azoturia originates from azote, the French word for nitrogen, indicating an abnormal amount of nitrogen in the urine. That is usually not the case in horses tying-up, hence azoturia is an incorrect name for the condition. The name Monday Morning Disease was applied years ago because so many work horses suffered the affliction when they went back to work following a weekend of rest.
Today the syndrome strikes on any day of the week, and it is seen most frequently in mares normally getting a consistent amount of healthy exercise and plenty of feed--in other words, "performance horses." Dr. Alice explains that tying-up can occur in many different types of performance horses and for several different reasons. Tying-up, she adds, can happen when an endurance horse becomes exhausted or sweats excessively, resulting in an electrolyte imbalance.
Dr. Alice says many cases of tying-up, however, result from a metabolic disorder related to having too much calcium in the diet. The over-abundance of calcium comes from calcium rich alfalfa or calcium high supplements.
This overdosing of calcium leads to suppression of the parathyroid gland which regulates the calcium level in the blood, Dr. Alice explains. The suppressed parathyroid is unable to replace the large amounts of calcium used by nervous energy and muscle usage, and the muscles suffer tetany, sustained muscle contraction.
"As simple as it may sound, it is my experience that controlling the amount of calcium in diet eliminates tying-up," says Dr. Alice. Discontinuing supplements with calcium and feeding reduced amounts of alfalfa are usually all that is required, she adds.
Tying-up syndrome is characterized by muscle stiffness, especially of the hindquarters and loin, at times profuse sweating, reddish brown to almost black urine and obvious signs of pain.
Tying-up hits suddenly. The horse appears perfectly normal, maybe even a little on the "high" side when taken from the stall. Shortly after exercise begins, the visual signs appear. The horse's breathing may be hurried, and muscle stiffness is evident. In severe cases, complete lameness in the hindquarters will probably occur, and the horse could go down.
The horse will not want to move. Don't move the horse, Dr. Alice emphasizes. Start helping the horse by leaving him right where he is. Then devise an effective plan to relieve pain and make the horse more comfortable. If possible, blanket the horse while waiting for veterinary assistance.
If the horse is not in too much distress, walk him slowly to his stall or corral. Most veterinarians treat tying-up syndrome cases by first giving the horse a tranquilizer, which helps relax the muscles, plus an injection of vitamin E, calcium and selenium. The horse is then rested for a day, after which it can begin a very light exercise program.
The horse's diet may be changed, but usually in the wrong way. The calcium intake is not corrected. Instead many vets still recommend the horse not be given grain for a day or two, and then be given grain in small amounts, increased gradually each day.
Forget the old ways. If you want to avoid the tying-up syndrome, control the amount of calcium in your horse's diet. Try it, you'll like it!