Poor her and poor pup! Could have had a liver shunt- which causes toxins to build up in the system and make the dog go a bit weird!
Cocker rage is a form of epilepsy and is genetic, found mostly on the solid coated lines. Not common in springers as I understand it.
I have a lovely collie cross, whom at 12 weeks would have been put down by the vet due to bein too aggressive- he had been very heavy handidly toilet trained and was very head shy and realises aggressive- like he really meant the bites and growles. But with correct handling and patience within two weeks he was a lovely bit slightly nervous pup. It took till 2 years old to come out of his shell. Most puppies can be turned round, if they don't have an underlying condition. Also could the toxins from the very heavy worm burden or he cod have had a worm cyst in his brain which made him agressive.
Bloody back yard breeders- give proper breeders a bad name. Yes too many dogs are in the world, many with awfull genetic problems, but if we don't throw the good ones back in the gene pool there wl be no dogs.
Trying to educAte pet dog owners on not breeding is so hard, they just don't get that their one litter cos they want the kids to see baby puppies or want a pup from their bitch so don do any health tests etc, is why dogs are so screwed up!
Sorry vent over!!