Perineural botulinum toxin type A for management of femoral neuropathic pain in a dog ( Canis familiaris )

A 9‐year‐old male Welsh sheepdog presented with a longstanding history of pain (decreased weight‐bearing, hyperalgesia, allodynia) associated with the right femoral nerve. Previous responses to systemic medications (NSAIDs, gabapentin, amitriptyline) were poor. Improvements associated with amantadine were limited by gastrointestinal side effects. Partial responses were observed to oral administration of prednisolone and ivabradine. Perineural depot steroid injections were initially associated with 4‐week duration improvements but, following repeated treatments, improvements became short‐lived and signs of iatrogenic hyperadrenocorticism were more pronounced. Following a literature review and discussion with colleagues regarding the ethical implications, perineural botulinum toxin A was administered proximate to the right femoral nerve via an ultrasound and nerve stimulator‐guided approach. Improvement in the ability to lie down and negotiate stairs was noted at 6 hours after injection, and allodynia had resolved at 6 days after injection. Follow‐up indicates that the improvement was maintained for 12 weeks. A repeated treatment 16 weeks later than the initial injection was again associated with clinical improvement.