All horses show normal nerve sensation or sensitivity in the legs. Where that sensation is increased beyond normal limits it is termed “hypersensitivity”.
Overly sensitive legs could give a horse an unfair advantage [as they would be more careful to avoid hitting jumps] and are a concern on welfare grounds.
Hypersensitivity can be caused by a range of normal things, including injuries and infections, as well as malpractice.
No intentional hypersensitising has ever been proved [although it happened accidentally at the Beijing Olympics in 2008].
FEI vets test for hypersensitivity by thermographic [thermal imaging to identify hot spots] and clinical examination [by palpation].
If hypersensitivity is found a further examination is made at a later time to confirm the persistence of the condition.
The ground jury then takes a decision on whether to disqualify the horse on welfare grounds. No appeal is allowed.
This news story was first published in the current issue of Horse & Hound (15 September, 2011)