Neurogenic keratoconjunctivitis sicca in 34 dogs: A case series.

Objective: To describe the clinical findings, imaging features, underlying conditions, treatment, and progression of dogs presented between 2010 and 2019 with neurogenic keratoconjunctivitis sicca (NKCS).

Methods: Dogs diagnosed with NKCS were searched in the clinical database. Inclusion criteria were STT-1 readings <15 mm/min, clinical signs of KCS with concurrent ipsilateral xeromycteria.

Results: Thirty-four cases were identified. Mean age at presentation was 8.2 years, median 8.9 years (0.3-14.7). Twenty dogs were male, and 14 dogs were female. Concurrent neurological deficits included facial neuropathy (n = 13, 38%), peripheral vestibular syndrome (n = 10, 29%), and Horner's syndrome (n = 5, 15%). Advanced imaging was acquired in 53% of cases (n = 18). Etiologies included idiopathic (n = 18, 53%), endocrinopathy (n = 6, 18%), otitis interna (n = 4, 12%), head trauma (n = 3, 9%), iatrogenic (post-TECA-LBO, n = 1, 3%), brainstem mass (n = 1, 3%), and an area of inflammation in the pterygopalatine fossa (n = 1, 3%). Treatment for NKCS was initiated in most cases (n = 30, 88%) including: oral pilocarpine 2% and lacrimostimulant (n = 19), oral pilocarpine 2% only (n = 3), or lacrimostimulant only (n = 8). A mean time follow-up of 3.7 months, median 3 months (1-14) was available in 23 cases (68%). Eleven cases with follow-up were responsive (48%) with resolution of the clinical signs in a median time 4 months (1-10), and all of them were treated with oral pilocarpine (±lacrimostimulant).

Conclusions: Most cases presented as idiopathic NKCS; in others, an underlying cause of facial neuropathy was identified. All responsive cases were treated with oral pilocarpine 2%.