Feline Osteomyelitis Study Guide

Overview and Clinical Importance

Osteomyelitis is the inflammation and infection of the medullary cavity, cortex, and periosteum of bone, most frequently caused by bacterial or fungal organisms. In cats, osteomyelitis is relatively uncommon compared to dogs but represents a clinically significant condition that requires accurate diagnosis and aggressive treatment. The condition is characterized by lameness, swelling, heat, pain, draining tracts, and localized erythema.

Feline osteomyelitis most commonly results from cat bite wounds, which introduce bacteria deep into tissues through puncture wounds. Other causes include surgical contamination (post-operative), open fractures, and hematogenous spread from distant infection sites. The condition can be acute or chronic, with chronic cases being more challenging to treat due to sequestrum formation and bacterial biofilms.

Etiology and Pathophysiology

Routes of Infection

Direct Inoculation (Most Common): This occurs through bite wounds, open fractures, surgical contamination, or penetrating injuries. Cat bites are particularly problematic because the narrow, deep puncture wounds heal quickly superficially, trapping bacteria in deep tissues and creating an anaerobic environment.