Tear production as measured by Schirmer tear test-1 in dogs with atopic dermatitis

The objective was to measure tear production using Schirmer tear test-1 (STT-1) in dogs with atopic dermatitis, to evaluate for abnormal tear production.

We evaluated 47 client-owned dogs diagnosed with atopic dermatitis based on history, clinical signs, completion of an elimination diet trial, and fulfillment of at least 5 of Favrot's diagnostic criteria.

Schirmer tear test-1 was conducted on each dog. Values < 15 mm/min were consistent with low tear production and suggestive of keratoconjunctivitis sicca. Values > 25 mm/min were consistent with epiphora due to excess lacrimation.

Twenty-one of 47 atopic dogs had STT-1 values outside the normal range in at least 1 eye. Three had STT-1 values < 15 mm/min and 18 had STT-1 values > 25 mm/min in at least 1 eye.

These findings suggest atopic dermatitis may be associated with altered tear production. However, the absence of a complete ophthalmic assessment precludes definitive conclusions regarding keratoconjunctivitis sicca and epiphora. Future studies to validate these observations could help determine whether routine screening of atopic dogs using the STT-1 can aid in detecting ocular manifestations of canine atopic dermatitis to optimize animal care.