I remember watching an Embarrassing Illness show about animals, and there were a couple of dogs with major sexual appetite/behaviour issues (one used to masturbate and the other used to hump the cat all the time) - each of these dogs was entire and then castrated after the advice of the vets on the show and the behaviours in question stopped. The owners didn't want to get their dogs done in the first place because they thought it would "make them less of a dog". One was also worried about the op as he'd had a previous dog (with testicular cancer) who didn't make it through an op, which would make one nervous. My point is, is that lots of owners want to keep their dogs whole to keep them macho. Presumably this isn't really the case with cocker owners, as they're not exactly the most macho of dogs! Maybe those people would be the kind of people who'd get implants for their dogs.