Ocular Manifestations in Dogs With Facial Nerve Dysfunction

To characterize the spectrum and frequency of ocular abnormalities associated with facial nerve dysfunction (FND) in dogs and to assess clinical outcomes, with specific comparison between brachycephalic (BC) and non-brachycephalic (NBC) breeds: METHODS: Medical records of dogs with FND evaluated between 2009 and 2023 at the Ophthalmology Service of the Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, were retrospectively reviewed.

Seventy-four dogs (84 eyes) were included, with French Bulldog being the most frequently affected breed (20; 27.0%). Facial nerve paralysis affected 63.1% of eyes, whereas paresis affected 36.9%. The main etiologies were idiopathic (14.9%), iatrogenic (13.5%), and otitis media/interna (12.2%). Corneal sensitivity and Schirmer tear test I were significantly reduced in affected eyes, without significant differences between skull types. Ulcerative keratitis occurred in 61.9% of eyes, being more frequent and severe in BC dogs (p = 0.007). Facial function recovered in 47.6% of dogs. Recovery was unaffected by age or skull type, differed significantly by sex (p = 0.043), and tended to be higher in dogs with paresis (p = 0.075). Worse ocular outcomes were linked to lower esthesiometry values (p = 0.023) and to the presence of anterior uveitis (p = 0.037). At the end of the study, 14 eyes (17.6%) were enucleated.

FND carries a guarded prognosis in dogs, with fewer than half achieving functional recovery. Ocular surface disorders, particularly neurogenic keratoconjunctivitis sicca and neuroparalytic ulcerative keratitis, were frequent and often led to poor outcomes, especially in BC dogs. Early ophthalmic management is crucial to preserve vision.