 Other less common conditions which appear in the breed include <unk> <unk> , which is where elevated levels of alpha @-@ <unk> acid are in the dog 's urine , blood plasma , and spinal fluid . It can cause seizures , muscle stiffness , and ataxia , but is more commonly found in Staffordshire Bull Terriers . A degeneration of the hip joint , known as Legg – Calvé – Perthes syndrome , also occurs in the breed . However , the chances of this condition occurring are much higher in some other breeds , such as the Australian Shepherd and the Miniature Pincher . The breed is also one of the least likely to be affected by a luxating patella , where the knee cap slips out of place . 
