Spine and tail
The gene that shortens the tail is usually harmless. Now and then a kitten is born with no tail at all. In such a cat the end of the spine can be too short as well, so it may find jumping hard or have trouble holding its wee and poo. How often this happens is not known.
How it is found: No DNA test. Breeders do not use tailless cats and do not breed from cats with spine problems.






