First case of presumed trigemino-oculomotor synkinesis in a dog.

An 11-year old, intact male Border Collie was referred with a history of subacute and progressive left eye exophthalmos and mydriasis associated with reduced pupillary light reflex, ventrolateral strabismus, and absence of physiologic nystagmus in the left eye. Neuroanatomical localization was consistent with a left oculomotor neuropathy, involving the general somatic and visceral parasympathetic efferent components. Computed tomography and magnetic resonance imaging of the head were performed.