Incidence and risk factors for exertional rhabdomyolysis in thoroughbred racehorses in the United Kingdom

Abstract

Telephone surveys of 34 racing yards with 1276 horses in training were made to establish the overall incidence of exertional rhabdomyolysis in the previous year. A case-control study was used to investigate the risk factors for the syndrome in 12 yards selected on the basis of the routine confirmation of diagnoses by the evaluation of the serum activities of creatine kinase and aspartate aminotransferase. The overall incidence of the syndrome was 6.7 per cent and 80 per cent of the trainers had at least one affected horse. In 74 per cent of the affected horses it frequently recurred, with an average of six lost training days per episode. Risk factors identified for the syndrome included being female, having a nervous, excitable temperament, and being two years old.

Heritability of Recurrent Exertional Rhabdomyolysis in Standardbred and Thoroughbred Racehorses Derived From SNP Genotyping Data

“…In Thoroughbred racehorses, epidemiological studies have concluded that diet, exercise, sex, age, and stress are risk factors for development of clinical disease (MacLeay et al 1999a;McGowan et al 2002;Upjohn et al 2005). In 2010, Isgren et al identified similar risk factors in cases of RER in Standardbred racehorses, consistent with the hypothesis that RER in both breeds is phenotypically similar but also share the same risk factors.…”

“…Muscle biopsy is predominantly utilized to rule-out other potential causes of ER, but may show nonspecific myopathic features such as centrally located nuclei and variable degrees of necrosis and regeneration (Valberg et al 1993;Valberg et al 1999). Estimated prevalence of RER is 6% in Standardbred racehorses and ranges from 5% to 10% in Thoroughbreds (MacLeay et al 1999b;McGowan et al 2002;Isgren et al 2010). This relatively high prevalence has a significant financial impact on the racing industry, with an average of 5.8 consecutive training days lost per episode of RER in Thoroughbred racehorses (Jeffcott et al 1982).…”

Monitoring changes in skin temperature associated with exercise in horses on a water treadmill by use of infrared thermography

“…The higher temperature compared to our study findings may be a reflection of the temperature collection method of muscle biopsy rather than surface temperature. As exercise intensity increases so does the temperature of working muscle (Geor et al, 2000;McGowan et al, 2002). Therefore, the larger increase in surface temperatures recorded with the addition of water during this study suggest that the increased resistance provided by the water resulted in higher muscle activity (contraction of tissue and alterations in bloodflow) that was able to be detected using IRT.…”

Hereditary skeletal muscle diseases in the horse. A review

“…Various risk factors have been identified (40). It is especially seen in young, female Thoroughbred racehorses with a nervous temperament (40,43).…”

“…Various risk factors have been identified (40). It is especially seen in young, female Thoroughbred racehorses with a nervous temperament (40,43). The condition occurs more frequently following a period of rest while being maintained on a high carbohydrate diet (28 (44).…”