This is really an interesting topic, I'm learning a lot. I had never heard about the rage issue with Cockers, altho now that I recall a friend's Cocker, I can see that my friend's dog no doubt had some issues along those lines. He pretty much had to keep his dog away from all people at all times, it would just snap and try and bite. And if you stopped by to visit you had to be darn sure to never approach the dog and keep your hands away, if you didn't approach the dog, the dog was OK. I do give my friend credit for working with the dog tho, he and the dog got along great, and he was a responsible owner by keeping the dog away from people (he got this dog when the dog was already a mature dog). He is a single guy with no kids, and there were never any kids around the dog.
Sort of off track here but, a friend of mine takes her dog to the dog park pretty frequently, she has a very large dog, and she has had several run ins with aggressive dogs attacking her dog. She has had to take him to the vet once already to have a torn ear checked out. She had asked me at one time if I wanted to bring my 2 dogs with her to the dog park, and I told her absolutely no way. I know that most dog parks are fairly safe, but I have heard too many horror stories about the dog park here in our city. There are too many irresponsible dog owners in my area that like to own a pit bull-type dog for the wrong reasons (nothing wrong with the pit bull, it is some idiot people in my area). My 2 dogs are much too small and much too friendly for their own good to go to our dog park....it is a shame. In my area hunting dogs are popular, and a lot of the hunting dogs in my area, for some reason, are very hyper and some are very aggressive. So, no dog park for us!