Aberrant laryngeal location of Onchocerca lupi in a dog.

Onchocerca lupi (Spirurida, Onchocercidae) is an emerging vector-borne helminth that causes nodular lesions as- sociated with acute or chronic ocular disease in dogs and cats. Since its first description in dogs in 1991, this zoo- notic filarioid has been increasingly reported in Europe and the United States. An 8-year-old outdoor mixed- breed female dog from the Algarve (southern Portugal) was presented with a history of severe dyspnoea. Cervical and thoracic radiographs revealed a slight reduction in the diameter of the cervical trachea and a moderate in- crease in radiopacity of the laryngeal soft tissue. An exploratory laryngoscopy was performed, revealing filiform worms associated with stenosis of the thyroid cartilage and a purulent necrotic tissue in the larynx lumen. A sin- gle sessile nodule, protruding from the dorsal wall of the laryngeal lumen caused a severe reduction of the glottis and tracheal diameter. Fragments of the worms were morphologically and molecularly identified as O. lupi. His- tological examination of the nodule showed a granulomatous reaction with sections of coiled gravid female nem- atodes. Following laryngoscopy, a tracheostomy tube was inserted to relieve dyspnoea and ivermectin (300 μg/kg, once a week, for 8 weeks) combined with prednisolone was prescribed. The dog showed a complete recovery. Although O. lupi has been isolated in human patients from the spinal cord, this is the first report of an aberrant migration of O. lupi in a dog. The veterinary medical community should pay attention to aberrant loca- tion of O. lupi and consider onchocercosis as a differential diagnosis for airway obstruction in dogs.