Lie the dog on its side with the affected limb on top, hold the thigh bone in one hand and touch the patella with the other hand to check that the patella is in its normal position. If the patella is medial or lateral to the normal position, a patellar dislocation is identified. If the patella is in the normal position, pinch the patella or the ligament attached to the patella with the thumb and index finger and move the patella medially or laterally with slight pressure to determine the degree of patellar ligament stability. If the patella or ligament moves significantly, the patella is unstable and a dislocation or imminent dislocation of the patella is likely to occur.
