Causes visual impairment, confusion, erratic temperaments, and apparent loss of memory for previously learned tasks. A fissure in the roof of the mouth and upper lip, may be present together or separately. Abnormal formation of the body of the vertebra, can cause posterior ataxia and paralysis. It causes the twisted tail in the screw tailed breeds. Aseptic necrosis of the head and neck of the femur, causes rear leg lameness.
Upper jaw extends beyond the lower jaw.
Radius stops growing sooner than the ulna causing bowed front legs. Lower jaw extends beyond the upper jaw. Improper formation of cartilaginous rings of the trachea causing mild to severe breathing problems. A small trachea due to improper development causes mild to severe breathing difficulties. Absence of most if not all teeth.