Myopathies in sport horses and the importance of feeding

Exertional myopathies are a group of pathologies of variable etiology characterized by the presence of muscle pain and impaired performance during or after exercise. Recurrent and sporadic rhabdomyolysis (RER), polysaccharide storage myopathy type 1 and 2 (PSSM1 and PSSM2), and myofibrillar myopathy (MFM) are included under this concept. These can occur both sporadically, generally associated with extrinsic factors, including nutrition, and chronically associated with intrinsic muscle fiber abnormalities. The identification and elimination of the triggering factors is what will make it possible to prevent future episodes. Both nutritional management and a training plan focused on compensating for the underlying deficiencies are two basic pillars in the strategic management and treatment of horses suffering from these pathologies. One of the keys to management is to control the energy source and reduce the non-structural carbohydrate content of the diet (NSC). However, there is no single treatment; rather, treatment must be tailored to the specific myopathy and the individual. This article aims to summarize the knowledge to date on the etiology, symptomatology and diagnosis of each pathology and to present a specific nutritional program that allows the design of a balanced diet with an adequate caloric intake, protein level, minerals and vitamins for each case.