Q: My 15h eight-year-old cob mare’s back legs shiver. It happens when I am putting her feet back down after picking them out. I have the farrier to her regularly, and she isn’t shod.
Is this a progressive condition and is it hereditary? I am thinking of treating her to a few equine muscle release therapy sessions, as I think they may help.
Jo Holmes MRCVS replies:Shivering describes a difficulty in raising one hind limb at a time and balancing on three legs.
It is most common in draught breeds and tends to be progressive. In its worst form, it can make shoeing and foot balancing almost impossible.
However, shivering does not necessarily make a horse unsafe to ride – several horses I know of have continued to work, even evented, to a high level despite the condition.
Shivering is generally most noticeable as a mild muscle tremor through the hindquarters and tail during movement, when picking out the hind feet or attempting hind limb flexion tests at pre-purchase examination.
Little is known about the causes, and its heritability cannot be ruledout, although this has not yet been proven.
It could be caused by nerve or muscle damage or spinal cord disease. Toxic plants – noticeably sweet pea – have been implicated in some countries, so it could be worth checking your pasture for these.
Otherwise, monitor your mare’s clinical signs carefully. I’d be interested to hear whether the muscle release therapy produces any improvement.