A 7-month-old, female Rough Collie with a history of diagnosis and treatment for steroid-responsive meningitis-arteritis was presented with a history of recurrent fever and lethargy and progressive lameness.
Magnetic resonance imaging revealed a large fluid intensity lesion (T2W hyperintense to muscle, T1W hypointense and in both sequences isointense to joint fluid) centred on the medial aspect of the right shoulder joint with outpouching into the surrounding muscle.