Bone Fracture/Luxation in a young Border Collie with Sensory Neuropathy
Contributed by Dr. Mark Bush
Sourthern Counties Veterinary Specialists
Hangersley, Ringwood, Hampshire, UK
Clinical History
A five-month-old male Border Collie puppy was evaluated for a right central tarsal bone luxation (below, top left and right) which was repaired with a 2.0 mm positional screw and washer (below, bottom left and right). A dressing was applied to the distal right pelvic limb and replaced on a weekly basis while the puppy was managed on an outpatient basis with instructions for strict exercise restriction.
Pre-OP
Pre-Op
Post-Op
Post-Op
After four weeks, a worsening of the right pelvic limb lameness was apparent associated with a calcaneal fracture (below, pre-op). Surgery to repair the calcaneal fracture was performed with a 1.6 mm pin and 1 mm tension band wire (below, pre-op). Instructions for strict exercise restriction were repeated and weekly dressing changes continued
Pre-Op
Post-Op
Post-Op
Physical and Neurological Examination
At the next follow-up examination pelvic limb ataxia was apparent. Upon further questioning of the client, a slowly progressive ataxia and intermittent scuffing of both pelvic limb paws was noted. Examination one week later revealed tetraplegia and a complete absence of pain sensation distally in all four limbs. A sensory polyneuropathy, as previously reported in Border Collies (Harkin et al, 2005), was suspected.
Conclusion
Due to the poor prognosis and lack of available treatments, the puppy was euthanized and a post-mortem examination performed to collect samples of the radial, median, ulnar and peroneal nerves. Regional nerve fiber loss was evident in all nerves. Unfortunately it is not possible to distinguish sensory from motor nerve fibers in resin sections of mixed nerves, but given the clinical presentation, the depleted fibers are likely sensory.
Image below: Toluidine blue-basic fuschin stained resin section of the peroneal nerve from this puppy with sensory polyneuropathy. Note multifocal areas of nerve fiber paucity. Magnification X400
