Another strange comment I've heard more than once is that more dogs have hip dysplasia now they don't have docked tails 
Problem I find is that who really knows how many dogs (of any breed) have things like HD.
In my research on docked and undocked tails, I have been told by a couple of cocker breeders that, having been used to docked tails for over 100 years and now having long tails, the breed is experiencing an increase in HD. The suggestion is that cockers are not used to the additional strain on the spine and hips. I disregarded this unconfirmed assertion as nonsense, but reading some comments here, maybe there is some substance to the claim? I don't know. Any comments?