The objectives of this study were to determine to applicability of a cotton thread test as a new method for the evaluation of tear secretion in healthy male and female lambs and to establish normal values in these animals.

The study was performed on 30 healthy Awassi lambs at the age of 1 to 3 days. The animals were divided into two groups, as group I (15 male lambs) and group II (15 female lambs). The phenol red impregnated thread was inserted into the recessus conjunctiva inferior for measuring tear secretion. After 15 seconds, the thread was removed and wet portion of the thread was measured in milimeter.

The mean cotton thread test values of 60 eyes of 30 lambs were 25.61±5.36 mm. Mean values of right and left eyes were found as 27.93±5.75 and 27.53±6.80 mm respectively, in group I. These values were 23.80±3.78 and 23.20±2.86 mm in group II, respectively. There was no significant difference between the values of right and left eyes, but significant differences (p<0.05) occurred between the two groups in either right and left eyes.

As a result, it was concluded that the cotton thread test was an easily and rapidly performed diagnostic tool for determining tear production and these measured values could be accepted as reference for healthy lambs.