Short spine syndrome is a very rare congenital defect. Part of awareness Tilly raises is to never breed dogs with short spine syndrome.
Here is more Tilly:

Short spine syndrome is a very rare congenital defect. Part of awareness Tilly raises is to never breed dogs with short spine syndrome.
Here is more Tilly:

Tilly: has a tricky spine condition
Also Tilly: banned from sex for ethical reasons
Poor Tilly, have they not suffered enough!?