Several juvenile diseases affect the canine forelimb. The most common are hypertrophic osteodystrophy, panosteitis, and retained cartilaginous core. Panosteitis and hypertrophic osteodystrophy tend to be self-limiting, with a good long-term prognosis, although severe cases can develop. These diseases may recur during growth. Severe cases of hypertrophic osteodystrophy can lead to angular limb deformities and may even be fatal. Retained cartilaginous cores can be benign with no evidence of clinical signs and be found incidentally on radiographs. However, if they disrupt the distal ulnar physis, angular limb deformities may persist requiring surgical intervention with a corrective osteotomy.