The markings are clearly defined and there is a trace of a black line extending from the occiput to the tail. The tail, which the American Kennel Club described as 'a perfect double-curl', normally curls tightly over the hip.Pugs have two distinct shapes for their ears, 'rose' and 'button'. The curled tail of a British bulldog is an example of a hemivertebrae, but when it occurs not in the coccygeal vertebrae but in other areas of the spine, it can cause paralysis. The condition occurs when two parts of a spinal vertebra do not fuse properly while a young Pug is still growing, resulting in an irregularly shaped spinal cavity which can put pressure on the spinal cord.