Infectious bovine keratoconjunctivitis: contact transmission

Area of Science:

• Veterinary Microbiology
• Animal Ophthalmology
• Bovine Diseases

Background:

• Infectious bovine keratoconjunctivitis (IBK) is a common eye disease in cattle.
• Moraxella bovis is the primary bacterial pathogen associated with IBK.
• The role of environmental factors and vectors in M. bovis transmission is not fully understood.

Purpose of the Study:

• To investigate the transmission dynamics of Moraxella bovis in calves.
• To assess the importance of M. bovis transmission in the absence of face flies and environmental insults.
• To determine the efficacy of herd preventive treatments under minimal risk conditions.

Main Methods:

• Thirty calves were used, divided into 10 groups.
• Each group consisted of 1 experimentally infected calf and 2 contact calves.
• Calves were monitored for 40 days for clinical signs and bacterial recovery.

Main Results:

• Only 1 contact calf developed clinical infectious bovine keratoconjunctivitis.
• Moraxella bovis was recovered from only 8 of 20 contact calves.
• All experimentally infected calves showed infection and disease.

Conclusions:

• Transmission of Moraxella bovis without face flies or environmental factors is of minimal importance.
• Herd preventive treatments for IBK are most effective when flies and environmental factors are minimized.