Tying up
Tying-up (also known as ER = equine exertional rhabdomyolysis or RER = recurrent equine exertional rhabdomyolysis) is a muscle disorder that occurs more frequently in thoroughbreds and standardbreds (particularly in nervous mares). The horse’s muscles is damaged in the process and causes severe pain. Affected horses are reluctant to move, stiff and appear lacking in energy. To date, no genetic mutation has been identified as the exact cause. It is thought to be based on changes in the cell’s own calcium regulation. Triggering factors can include: electrolyte imbalance (salt or potassium deficiency after extensive sweating), a ration low in raw fibre and high in grain, and training following “rest days” combined with energy-rich feeding at the same time. This is why it is also referred to as “Monday morning disease”.
As a preventive measure, feeds low in grain and sugar are recommended. Energy should be supplied via hay from an early first cut and fat-rich concentrate feed. A high vitamin E supply, sufficient salt and electrolyte intake to cover requirements, as well as selenium intake, are important. Stress should also be reduced as much as possible.
