Often seen in smaller dog breeds including the Cavalier King Charles Spaniel, patellar luxation refers to a slipped kneecap. A genetic deformity of the femur (thigh bone) causes the patella, or kneecap, to shift out of place (luxate) and become misaligned. In small dog breeds, the patella typically shifts toward the inside of the rear leg, called medial luxation. In larger breeds, the patella tends to slip towards the outside of the rear leg, referred to as lateral luxation.
This congenital condition is most often observed when a puppy is 4 to 6 months old. Affected dogs may appear to have occasional lameness. Or the dog may “skip” about until the kneecap pops back into place.
If you believe this condition may be present in your Cavalier King Charles Spaniel puppy, your vet can conduct a physical examination and take x-rays. In mild cases, where the patella slips only occasionally, treatment may be unnecessary. In more serious cases, surgery may be indicated.