Dogs do have knees. They have two knees located on their hind legs, similar to humans. Each knee consists of the femur (thigh bone), tibia (shin bone), and the patella (kneecap). Dogs' knees function as hinge joints stabilized by ligaments, muscles, and cartilage, enabling movement and support for walking and running on all four legs. Common knee problems in dogs include patellar luxation and cruciate ligament tears, similar to knee injuries in humans.