Measurement of tear production and establishment of reference values in guinea pigs (Cavia porcellus) using a modified Schirmer tear test

The authors recommend values above 8 mm at 30 seconds and 10 mm at 60 seconds to be considered normal when using a 2.5-mm STT strip. There are ambiguous areas at 5-8 mm and 6-10 mm. If in these ranges the results should be combined with clinical signs and judgement.