
Yep there is a world of difference between a rage syndrome dog and a dog with even the severest of behavioural problems - with the latter, there is SOME 'tell' there somewhere, they don't just behave aggressively for no reason but it might take a skilled behaviourist to figure out what the trigger or reason is, and it might well have morphed into something YOU don't think is a valid reason.
I hear about and get called about quite a few spaniels (not just cockers but predominantly working cockers) who have owners who think they have a dog with rage syndrome - in 10+ years, not one of those dogs has been 'ragey' - I have been able to find a trigger, work back through what has happened and get the owner to SEE what is really going on.
Cockers unfortunately with their sharp smart nature AND their gundog desires to carry stuff around, suffer quite badly and quite easily if mishandled, from resource guarding, and they can very quickly become so bad they will guard a ridiculous object from a long distance. That is commonly the real issue - the dog is guarding something and that something is a/ small and not identified by the owner as worthy of guarding (a scrap of tissue for example), and b/ so far away that the owner cannot see it, or is not aware that it is there...
Unfortunately in these cases people leap to the rage conclusion, when really the answer is the wrong training and frequently the wrong dog for the situation.
You will not cure nor prevent a rage syndrome dog from having 'rage' outbursts by being 'firm' or 'no nonsense' or anything else with him - some of these tactics CAN however cause a dog to become very resource guardy/possession aggressive!
My top tips for cockers would be - buy from the background/lines that suit YOUR lifestyle - if you cannot offer work or an accurate recreation of work, don't buy a worker!
Always teach them to swap items and retrieve from day ONE.
Never EVER chase and chastise them for picking up stuff and running around with it - thats a sure fire way to create a resource guarder.