**Border Collie Collapse (BCC)** is a condition marked by exercise-induced episodes of abnormal gait or mentation in otherwise active and healthy dogs. In a detailed 2016 study, **S. Taylor** and colleagues evaluated clinical and metabolic responses to two standardized exercise protocols—ball-retrieving and sheep-herding—in **13 dogs diagnosed with BCC** compared to **16 unaffected Border Collies**.
The affected dogs exhibited clear post-exercise signs of **collapse, disorientation, or abnormal gait**, typically after intense physical activity. Despite exhibiting expected post-exercise physiological changes—elevated **rectal temperature, lactate, pulse**, and shifts in **blood gases**—no statistically significant differences were observed between the BCC group and control dogs.
Further evaluations including **electrocardiography**, **needle electromyography**, and **muscle biopsy** revealed no abnormalities to explain the collapse. Notably, genetic testing excluded two major mutations: the **dynamin-1 gene mutation** responsible for exercise-induced collapse in Labradors and the **V547A mutation** linked to malignant hyperthermia.
The researchers eliminated many common causes of **exercise intolerance**, but the underlying mechanism of BCC remains unknown. They concluded that while a **genetic basis is strongly suspected**, it has yet to be identified, underscoring the need for continued research into the pathophysiology of collapse in athletic dogs.
Source: S. Taylor, C. Shmon, E. Li-Su, T. Epp, K. Minor, J. Mickelson, E. Patterson, G. Shelton. Published in Journal of the American Animal Hospital Association, Volume 52(5), Pages 281–290, on September 2, 2016.
