Equine headshaking is a painful neurological condition causing involuntary, violent head movement that significantly impairs quality of life and usefulness.
Headshaking causes intense welfare suffering that is often underappreciated because the condition looks behavioral rather than painful to the uninitiated. Affected horses experience what researchers describe as a feeling of severe nasal irritation or facial pain equivalent to trigeminal neuralgia in humans. This neurological pain cannot be switched off by the horse and occurs involuntarily during exercise and in bright conditions. Horses with severe headshaking may be unable to work safely, may injure themselves or riders during headshaking episodes, and show signs of significant distress in affected conditions. Early diagnosis and access to PENS therapy - which has provided substantial relief in controlled trials - can dramatically improve welfare for affected horses.