Bacterial infective stifle arthritis secondary to a migrating grass seed foreign body in an adult dog

An adult neutered male cocker spaniel was presented with a 2-3week history of left pelvic limb lameness, stifle effusion, general malaise and pyrexia. Computed tomography (CT) imaging revealed an irregular tubular tract, extending from the stifle distally to the level of the mid tibial diaphysis, associated with the long digital extensor muscle. Ultrasonography revealed the tract had echogenic contents, however no foreign body could be identified. Following surgical exploration, a grass seed was identified in the medial compartment of the left stifle. Culture of the grass seed and joint capsule tissue yielded growth of Pantoea agglomerans. Following the surgery and subsequent antibacterial and non-steroidal anti-inflammatory medication, the dog made a full recovery to normal activity.