A 10 week old, intact female Labrador Retriever presented to the Emergency Service at the Cornell University Hospital for Animals (CUHA) in February 2012 following a four day history of progressive forelimb lameness, fever, and pinnal pustules. On presentation to CUHA, the dog was markedly painful and nonambulatory, with bilateral elbow joint effusion and significant soft tissue swelling over the elbows, forearms, and paws. Pustules were noted on the inner pinnae and chin. Differential diagnoses for the progressive lameness included panosteitis, hypertrophic osteodystrophy, vaccine reaction and septic arthritis. For the pinnal pustules, differential diagnoses included a vaccine reaction, juvenile cellulitis, and bacterial pyoderma. Radiographs of the forelimbs and cytology of the pinnal pustules and joint fluid, along with the development of panniculitis, pointed to a presumptive diagnosis of juvenile cellulits. The dog was treated with oral dexamethasone and symptomatic care. She made a full recovery following approximately one month of treatment.