Determination of Schirmer tear test‐1 values in clinically normal alpacas (Vicugña pacos) in North America

Purpose To determine the normal reference range for Schirmer tear test‐1 (STT‐1) values in eyes of healthy alpacas (Vicugña pacos). Methods Complete ophthalmic examinations were performed on forty healthy alpacas (80 eyes). STT‐1 values were obtained in both eyes of all alpacas using a commercial STT strip of a single lot number. Data were analyzed, using a doubly repeated measures ANOVA design, Student's paired t‐test, and Pearson correlation test, with P ≤ 0.05 considered significant. Results The STT‐1 values ± standard deviation (SD) were 20.80 ± 4.01 mm/min OD, 20.00 ± 4.13 mm/min OS, and 20.88 ± 4.04 mm/min OU (range 15.50–30.50 mm/min). No significant differences in STT‐1 were found between OD and OS. STT‐1 was not significantly affected by breed. Schirmer tear test‐1 values were significantly increased by 3.45 mm/min for every 10 year increase in age. Conclusions This study provides a reference range of STT‐1 in the healthy alpaca which can assist veterinarians in diagnosing potential keratoconjunctivitis sicca, tear film abnormalities, as well as ocular surface diseases in alpacas.