Corneal sensitivity in healthy bovine calves

Area of Science:

• Ophthalmology
• Veterinary Medicine
• Animal Science

Background:

• Corneal sensitivity is crucial for ocular health and protective reflexes.
• Limited data exists on corneal sensitivity in young bovine calves.
• Understanding corneal sensitivity in calves is important for diagnosing ocular conditions.

Purpose of the Study:

• To evaluate corneal sensitivity in healthy bovine calves using corneal touch threshold (CTT).
• To establish baseline CTT values for young cattle.
• To assess the feasibility of using Cochet-Bonnet aesthesiometry in calves.

Main Methods:

• Twelve clinically normal male Holstein calves (median age 76.5 days) were studied.
• Corneal touch threshold (CTT) of the central cornea was measured bilaterally using a Cochet-Bonnet aesthesiometer.
• A modified head restraint was employed for the procedure.

Main Results:

• The mean CTT was 1.33 ± 1.1 g/mm², with a wide range (0.62–66.15 g/mm²).
• Mean filament length was 34.56 ± 8.02 mm (range, 14–47.5 mm).
• No significant difference in CTT was observed between fellow eyes.

Conclusions:

• Cochet-Bonnet aesthesiometry was well-tolerated in calves.
• Calves may possess more sensitive central corneas compared to adult cattle.
• Significant individual and inter-eye variation in corneal sensitivity was noted.
• Larger studies are required to establish definitive reference ranges for calf corneal sensitivity.