The purpose of this study was to determine if a circadian rhythm exists in Schirmer's tear test (STT‐1) values in a group of healthy adult cats.
Twenty adult neutered Domestic Short‐haired cats (DSH) were used in the study.
Tear production was mea...
The purpose of this study was to determine if a circadian rhythm exists in Schirmer's tear test (STT‐1) values in a group of healthy adult cats.
Twenty adult neutered Domestic Short‐haired cats (DSH) were used in the study.
Tear production was measured with the Schirmer tear test (STT‐1) at 12 different time points over a 48‐hour period.
A significant difference (approximately 4.3 mm/min) was noted between STT‐1 values measured between 4 pm (lowest) and 12 am (highest) on both day 1 (P = 0.02) and day 2 (P = 0.01), and substantial variation in STT‐1 values was observed at different times during the 48‐hour period.
Significant variation in mean STT‐1 values demonstrates that there is a circadian rhythm in tear production in cats and thus shows the importance of taking the time of day into account when measuring STT‐1 in cats.