Presumed clostridial and aerobic bacterial infections of the cornea in two horses.

The research article describes the diagnosis and treatment of severe corneal infections in two horses that were suspected to be caused by Clostridium bacteria, aerobic bacteria, and possibly an insect.

Introduction

• This research was undertaken due to observations of severe corneal ulcers in two horses. These ulcers were initially assumed to have been caused by a type of bacteria called Clostridium.
• The corneal ulcers were further investigated using Gram-stained tissue samples from the horses. Large gram-positive rods were found, which suggested a clostridial infection.

Findings

• In one horse, Clostridium perfringens, a type of bacteria, was isolated from the tissue samples. However, in the second horse, no anaerobic organisms were detected.
• Additionally, aerobic bacterial cultures revealed the presence of Aeromonas hydrophila in the first horse and Enterobacter cloacae in the second horse.
• Notably, in the first horse, an insect exoskeleton was also found and thought to potentially be the cause of the corneal ulceration. However, in the second horse, a specific cause of ulceration could not be determined.

Treatments

• The corneal infections were tackled using various antibiotics, including an one-time subconjunctival injection of a combination of ticarcillin disodium and clavulanic acid. Additionally, chloramphenicol was used topically at regular intervals.
• In addition to these treatments, the second horse also received penicillin or trimethoprim-sulfadiazine.

Outcomes

• The treatments essentially led to the clearance of the corneal infections in both horses, with small leukomas, or scars, remaining between two and seven months after the initial evaluation.
• The application of chloramphenicol appeared to be effective against clostridial corneal infections in horses, pointing toward a potential treatment solution for such infections.