Tying-Up in Endurance Horses

A study investigated the incidence of tying-up (exertional rhabdomyolysis) in 101 horses participating in a 50-mile endurance race. Most of the horses were Arabian or half-Arabian, 75% were geldings and the average age was 11 years.

After a race, 38% of the horses had creatinine kinase (CK) levels higher than reported for resting horses. CK is an enzyme elevated due to the muscle damage associated with tying-up. However the degree of elevation was similar to that reported for normal endurance horses following a race. Elevated CK values indicative of tying-up were found in 4.5% of the horses. Only one animal was suspected of having a problem and pulled from the race following examination during the event. No significant association was found between CK levels and age, gender, muscle mass or temperament. 

No association was found with receiving electrolytes during the race, although CK activity following the race was significantly higher for horses that received a fat supplement in their diet. Finally, the gene mutations associated with polysaccharide storage myopathy were not identified in any of the horses so the underlying cause of the condition in these mostly Arabian horses remains unknown.

— Wilberger MS et al. EVJ 2015;47:165-170 

Shivers and Stringhalt

Two papers reported on a study of shivers and stringhalt. The authors used their resources and web-based survey to obtain videos and descriptions of suspected cases of shivers (27 confirmed cases and 67 suspected cases) and stringhalt (seven cases). Similar information was also collected for…