Fatal cerebral cuterebrosis in a dog.

A 4-year-old intact female Yorkshire Terrier presented an acute onset of hypersalivation and depressed mentation. The owner reported that the dog displayed tremors, right-sided torticollis, right-sided head tilt, and lifting of the left forelimb. The dog appeared restless and confused, and the condition progressed to lethargy and death on the way to an emergency hospital. At necropsy, a single 10 mm long x 1 mm wide, pale gray, botfly larva with black spines was found along the cerebral meninges. Areas of hemorrhage were noted in the right cerebral hemisphere. Microscopically, these areas also had evidence of necrosis and inflammation. Morphology of the larva allowed confirmation of subfamily-level identification as Cuterebrinae, and presumed genus-level identification of Cuterebra. Species-level identification of the larva as C. abdominalis was achieved through DNA extraction, PCR and sequencing at the cytochrome oxidase subunits 1 and 2 (COI and COII), followed by phylogenetic analysis. Aberrant cuterebrosis is a poorly documented condition in dogs that may cause neurologic signs and lead to death.