Management of an uncommon complication using botulinum toxin type A following prosthetic laryngoplasty

Summary An uncommon complication following prosthetic laryngoplasty was reported in a 4‐year‐old Andalusian mare. The mare was presented with a previously diagnosed left‐sided recurrent laryngeal neuropathy, after initial evaluation the mare underwent ventriculocordectomy and prosthetic laryngoplasty. After the procedure, the mare developed severe fluid accumulation within the surgical site, dysphagia and dorsal displacement of the soft palate. Due to severe clinical signs, a surgical revision was performed. The surgical site was drained, lavaged and a second prosthesis was placed, it was then closed in routine fashion. Following revision, the mare again developed fluid accumulation within 24 h, needle aspiration and the use of an active drain system did not eliminate the fluid production. Given the location of the surgical site and the large amount of fluid, it was suspected that trauma to the parotid salivary gland had occurred. After 10 days from the surgical revision, no signs of decrease in fluid production were observed. The mare was treated with intra‐glandular botulinum toxin, and fluid production ceased 5 days post‐injection. The mare was discharged from the hospital with no signs of dysphagia, dyspnoea, facial nerve paralysis, nor discharge from the surgical site 12 days post botulinum toxin injection. Follow‐up performed at 7 months confirmed the absence of clinical signs, and the mare had returned to her previous level of activity. This is the first case report of parotid salivary gland trauma as a complication after prosthetic laryngoplasty, and the use of botulinum toxin type A to manage this complication in a horse.