Monday Morning Sickness (tying up)

Exertional Rhabdomyolysis, commonly known by trainers as Monday Morning Sickness, also as azoturia, is a muscular disorder. The condition can range from mild stiffness of the musculature to actual cramping and recumbency (lying down for relief). The initial stiffness usually occurs in the neck muscles and over the gluteal areas. These animals will sweat excessively and have elevated cardiovascular and respiratory rates in addition to a slight increase in body temperature. When the muscles are palpated (feeling for pain), there is pain with only minor finger pressure. The muscles feel tense and stiff, especially along the longissimus dorsi and gluteal regions. Another classic symptom of these horses is myoglobinuria, which horsemen refer to as coffee-coloured urine.

This muscular disorder occurs when an animal is rested for a period of time during a training program and then returned to hard work. Endurance horses that are improperly trained will usually exhibit this myopathy after the first day of an event.

The origin of exertional rhabdomyolysis is not clearly understood. A change in the blood supply within the muscle tissue, a fluid and/or electrolyte imbalance, a genetic predisposition, or a nutritional influence have all been indicated in causing exertional rhabdomyolysis.

The only clinical sign that one would notice in a mild case is a slight change in the gait or merely that an animal is performing at a lower level than expected. There may be pain and stiffness upon palpation of the neck or gluteal musculature. In severe cases, the horses may exhibit extreme pain, reluctance to move, severe stiffness and sweating. It is in this stage that the animal usually exhibits myoglobinuria. Occasionally, these animals are in a state of recumbency.

Treatment of these animals should be focused on pain relief, a reduction in further muscle damage and the restoration of fluid and electrolyte balances. Infrared heat therapy using the Thermotex™ Infrared Therapy Systems Blanket has greatly reduced the inflammation within the muscles and greatly reduced the recovery time of these animals. In severe cases it is often advantageous to seek veterinary assistance to help with the pain management and fluid therapy. These treatments coupled with the therapy that the Thermotex™ Infrared Therapy Systems Blanket insures a speedy recovery and a return to athletic competition.