To evaluate corneal sensitivity as measured by the corneal touch threshold in healthy bovine calves.Animals Studied
Twelve clinically normal male calves with predominantly Holstein genetics and a median age of 76.5 days (range, 67–92 days).Procedures
Corneal touch threshold (CTT) of the central cornea was measured in both eyes of each calf using a Cochet-Bonnet aesthesiometer.Results
The mean ± standard deviation corneal touch threshold of all eyes was 1.33 ± 1.1 g/mm2 (range, 0.62–66.15 g/mm2), corresponding to a filament length of 34.56 ± 8.02 mm (range, 14–47.5 mm). There was no significant difference between fellow eyes.Conclusions
Cochet-Bonnet aesthesiometry was well tolerated in all 12 calves using a modified head restraint. Calves in this study may have a relatively sensitive central cornea compared to adult cattle and some other species; however, wide variation among individuals and eyes may be possible. Studies utilizing larger calf populations are necessary to establish reference ranges.