Canine hip dysplasia (abnormal development of the hip joint) begins when the hip joint in a young dog becomes loose or unstable. If left undiagnosed and untreated, this instability causes abnormal wear of the hip cartilage and ultimately progresses to osteoarthritis or degenerative joint disease. Signs of this condition are pain, reluctance to get up or exercise, difficulty climbing stairs, a “bunny-hopping” gait, limping, and lameness, especially after periods of inactivity or exercise. Hip dysplasia most commonly affects large- and giant-breed dogs; however, smaller dogs can also be affected. Although genetics often play a role in this disorder, young dogs that grow or gain weight too quickly or get too much high-impact exercise are also at risk. Being overweight can aggravate hip dysplasia.