A 12 week old female Shepherd/Labrador mix puppy presented to Cornell University Hospital for Animals for evaluation of progressive lameness, extreme lethargy, anorexia, and generalized paresis and pain. A diagnosis of Hypertrophic Osteodystrophy was made based on clinical signs and pathognomonic radiographic signs. Treatment with non-steroidal anti-inflammatory drugs and rest led improvement in clinical signs. Clinical signs, diagnostics, pathology, etiology, and treatment of hypertrophic osteodystrophy are discussed.