Hi
Is she a golden cocker? they are classically the ones that seem to suffer this. Are you meaning she has sudden bouts of unprovoked extreme aggression? Has she hurt anyone during them? If you have the chance and can keep a cool head without provoking her further you could take a video of her during one of these bouts. Take her and it along to a vet or an experienced pet behaviourist so that they can assess her and help you. Certainly behaviour problems are one big reason that dog's get passed on to another owner, its unfortunate and not very fair on anyone.
Cathy Wickenden BVet Med MRCVS
Barton Lodge Veterinary Centre
1 Midland Road, Hemel Hempstead, Hertfordshire, HP2 5BH
Tel: 01442 216048 24 hours
[
www.bartonlodgevets.co.uk]