Monday morning sickness in Horses

Monday Morning Disease often referred to as azoturia or exertional myopathy, is a significant exercise-associated muscular disorder affecting horses and generally appears during or soon after intense physical activity. The condition is frequently reported when horses are returned to heavy work following a rest period while continuing to receive energy-rich or grain-based diets. Clinically affected animals may show muscle rigidity, pain, excessive sweating, fatigue and unwillingness to move in more severe situations, the breakdown of muscle fibers releases myoglobin that can discolor the urine to a dark red or brown shade. The development of this disorder is influenced by several predisposing factors such as high carbohydrate feeding, poor physical conditioning, sudden increases in workload, electrolyte imbalances, inherited susceptibility and inappropriate feeding or management practices. From a pathogenic perspective the accumulation of glycogen in skeletal muscles followed by its rapid utilization during exercise leads to increased lactic acid production, metabolic imbalance and subsequent injury to muscle fibers. Effective management of the condition requires prompt rest, adequate fluid therapy, administration of anti-inflammatory drugs and proper dietary management, which together help in recovery and prevention of recurrence.