Evaluation of tear production using the Schirmer tear test I in healthy cats; effect of age, life stage, sex, breed and neuter status

Abstract

BackgroundThe purpose of this study was to evaluate the values of Schirmer tear test (STT) and determine effects of age, life stage, sex, breed and neuter status on tear production in healthy cats.MethodsThree hundred and forty-three domestic shorthair (DSH) and Persian cats, 50 days through 18 years old, were examined in this study. STT I was used to measure tear production in both eyes of each cat.ResultsA mean STT 14.9±4.8 mm/min was calculated for the eyes of all cats. There was a significant difference between STT values in kittens (≤6 months old) and cats of other age groups (P<0.001). A substantial number of cats with clinically normal eyes had STT values less than 10 mm/min. No significant difference was found between males (14.7±5.0 mm/min) and females (15.1±4.5 mm/min) in STT values (P=0.46). Significant differences were found between entire (14.4±4.2 mm/min) and neutered (16.2±4.1 mm/min) cats (P=0.001), and between STT values of DSH (14.6±5.0 mm/min) and Persian (16.5±3.1 mm/min) cats in the study population (P=0.001).ConclusionsThis study documents the average STT values for a sizeable feline population demonstrating that, in contradistinction to the situation in dogs, a number of cats with clinically normal eyes have STT values below 10 mm/min.

Tear film breakup time and Schirmer tear test in normal dogs: Effects of age, sex, reproductive status, skull type, and nasolacrimal duct patency

“…This finding was in line with a previous report on dogs 23 . In cats, sex is reported to have no effect on STT, whereas neuter status has been suggested to have an impact on STT 22 …”

“…7 In cats, a brachycephalic breed (Persian) has been reported to have higher tear production compared to domestic shorthaired cats. 22 In the present study, no significant correlation was observed between STT and TBUT in dogs. This finding was in agreement with the results of a study in which no correlation was found between TBUT and STT in cats experimentally infected with FHV-1.…”

“…23 In cats, sex is reported to have no effect on STT, whereas neuter status has been suggested to have an impact on STT. 22 Even age had no significant correlation with TBUT and STT, but a statistically insignificant increase in age was associated with a decrease in TBUT and STT in the dogs examined in this study. This finding was consistent with the significant reduction in STT in dogs with the increase of age.…”

“…In a study comparing tear production between brachycephalic and non‐brachycephalic dogs, the STT‐1 values were reported to be significantly higher in non‐brachycephalic dogs 7 . In cats, a brachycephalic breed (Persian) has been reported to have higher tear production compared to domestic short‐haired cats 22 …”

Normal reference ranges of ocular physiology and sonographic biometry of Latvian Hunting dogs

“…First, the SST strips were placed in the ventral conjunctival sack without difficulty and all dogs tolerated the test well. The STT has long been the clinical standard for evaluating aqueous tear production [17,18] and general reference values are known in different animal species such as dogs, cats, rabbits, and horses [19][20][21][22][23][24], and presumably, these values may differ among various dog breeds [23][24][25].…”