Telltale tail?
Q: Does a horse holding his tail to one side indicate lameness or neurologic disease? I recently passed on a horse for sale because he continually held his tail slightly to the right when he moved. When he stood still, his tail hung normally. The veterinary exam didn’t find any obvious issues, but I couldn’t get over the feeling that the unusual tail carriage indicated a problem.
Name withheld by request
A: Neutral tail position requires symmetrical muscle tension from no less than five pairs of muscles with intact vertebrae. There are a variety of non-lameness-associated reasons for asymmetric tail carriage: • breed type
• estrus behavior
• excitement
• trauma to tail base vertebrae • human manipulation (as seen in breeds like Saddlebreds)
• neurologic trauma after blocking • individual variation
In more than 30 years of sports medicine-based practice, I have seen asymmetric tail carriage associated with neurologic disease and severe lameness. However, in routine lameness evaluations (with inertial sensors and video documentation) I have not seen tail carriage change with diagnostic anesthesia of the hind limbs---that is, numbing of areas suspected of being the source of pain had no effect on tail carriage.
Keeping in mind that we form our opinions from our personal observations, I solicited opinions from several colleagues from a variety of other disciplines who also specialize in lameness diagnostics. Their experiences were similar.
Academic opinions on this topic are interesting. A 2014 paper by
Renate Weller, DVM, PhD, of the Royal Veterinary College in London found no significant relationship between tail carriage and lameness. However, a more recent paper by Sue Dyson, VetMB,
PhD, and Jan Van Dijk, DVM, PhD,
MRCVS, of the Animal Health Trust in Newmarket, England, determined that tail posture was one of 24 painassociated behaviors that improved with anesthesia of lameness. The variation in these conclusions is likely related to the study design where the second study was focused on behaviors under saddle while the first was based on measurement of tail angle.
From a more practical point of view, the best prognosticator of future performance is past history. In a prepurchase environment, a good work history, complete medical records and thorough clinical examination serve as your best guide. A comparison video demonstrating minimal change in tail carriage over time would also be very helpful. If the horse has a solid noninterrupted successful performance history, minimal medical intervention and a good clinical examination regarding neurologic and lameness evaluation (in hand and under saddle), I would not consider the tail carriage to be an element of risk.
Roland Thaler VMD, DACVSMR Metamora Equine PC
Davisburg, Michigan