Feeding Performance Horses with Myopathies
In combination with exercise, nutrition is an essential component of managing horses with myopathies. The optimal feeding program for an individual is tailored to the diagnosis of a specific underlying myopathy.
Exertional myopathies are defined by muscle pain and impaired performance during or after exercise. Exertional rhabdomyolysis (ER) represents a subset of exertional myopathies characterized by elevations in serum creatine kinase (CK) and aspartate transaminase (AST) activities. Forms of ER include type 1 polysaccharide storage myopathy (PSSM1), type 2 polysaccharide storage myopathy (PSSM2) in Quarter Horses, malignant hyperthermia, recurrent exertional rhabdomyolysis (RER), and myofibrillar myopathy (MFM) in Arabians.
There are other exertional myopathies, such as PSSM2 and MFM in Warmbloods, that are not typically characterized by elevations in serum CK and AST activities. Horses with these exertional myopathies have exercise intolerance and show reluctance to go forward, collect, and engage the hindquarters. Because these clinical signs are not specific to muscle disease, causes of decreased performance such as behavior, rider, tack, and orthopedic lameness need to be ruled out prior to investigating a primary exertional myopathy.
Altering diet and exercise regimes to compensate for underlying defects is often the best available strategy to assist horses with exertional myopathies. In this paper, Joe D. Pagan, Ph.D., and Stephanie J. Valberg, D.V.M., Ph.D., discuss feeding recommendations for horses with:
- sporadic exertional rhabdomyolysis,
- recurrent exertional rhabdomyolysis,
- type 1 polysaccharide storage myopathy, and
- type 2 polysaccharide storage myopathy and myofibrillar myopathy.
Pagan, J.D., and S.J. Valberg. 2020. Feeding performance horses with myopathies. In: Proc. American Association of Equine Practitioners Convention 66:66-74.
Open Publication