Dogs do not get along (SOMETIMES)

Question
We have a two year old English Bulldog.  About three months ago, we got a six week old American Bulldog puppy. At first, Rose, our English, was jealous, peed on the bed, etc...but never showed aggression toward the new puppy.  It seems like about three weeks ago, Rose began treating Lucy, our American, like a fellow adult dog and has become very aggressive toward her.  Both of my dogs now have scratches and sores all over there bodies from the stand-offs.  We are afraid we will have to get rid of one and can't bring ourselves to decide which one.  But, they are hurting each other...what can we do to help this behavior?

Answer
this isn't about "sometimes"..this is about ALL the time.  I have no idea how old this puppy is now, but there is a serious problem developing.  Getting a same sex puppy, especially one of a breed temperament much like the dog you already own, is a huge error.  Your English was already making statements of rank when she began marking your bed.  This was a clear indication that she perceived the puppy as a threat, whether or not this is a lack of socialization to younger dogs or simply a rank issue is impossible for me to determine from what you've told me.  However, this situation does NOT bode well for the younger dog in terms of dog-to-dog socialization and it certainly does not bode well in terms of future relationship between the two.

You need in person evaluation of both dogs and the developing situation which will involve extensive interview.  This problem can't be adequately addressed in this venue, since the real information required is something that one cannot ascertain from reading.  The likelihood of this relationship between dogs being readily available to rehabilitation is most like 50% and depends upon the skill and experience of the expert.  I suggest you contact the veterinary college in your geographical area and ask for referral.  Meanwhile, you must defer to the English by feeding, petting and interacting with her first while, at the same time, using positive reinforcement training to teach both dogs (separately) one specific behavior they can offer you for all attention.  This is a short fall therapy intended to place both dogs psychologically and emotionally in a frame of reference that defers to you (especially the English, but you cannot institute this merely for her as she will observe that the puppy does not have to earn anything and it will make matters worse).