North American Veterinary Licensing Examination (NAVLE) Practice Test

Infectious bovine keratoconjunctivitis, commonly referred to as pink eye, is primarily caused by Moraxella bovis. This bacterium is known to infect the conjunctiva and cornea of cattle, leading to significant inflammation and discomfort. Moraxella bovis is characterized by its gram-negative, rod-shaped structure and its ability to adhere to the surface of the eye, which can be facilitated by environmental factors such as dust, bright sunlight, or the presence of other irritants.

It is important to recognize that while other organisms such as Thelazia, Histophilus somni, and E. coli may play roles in various ocular or bovine diseases, they are not the primary causative agents of infectious bovine keratoconjunctivitis. Thelazia and Histophilus somni are more associated with different types of infections or conditions in cattle, while E. coli generally does not contribute to this particular eye disease. Therefore, the association of Moraxella bovis with infectious bovine keratoconjunctivitis highlights its significance in bovine ophthalmic health.