9 mo. old puppy biting/attacking older family dog

Question
Hello, I am getting mixed advise from trainers/behaviorists regarding my new male puppy's (we have had him since he was 5 mos-no history available) behavior with our older female English Bulldog. He is a Lab/Basenji mix who is very very active, intelligent, easy to train w/ treats/positive reenforcement. He has some problems in some areas such as recall that need work, but I am confidant that we can work with these. My biggest problem is that he will attack and vigorously, repeatedly bite her whenever he gets the chance. This started out as what I thought was play, I tried letting her "correct" him, and thought it would resolve itself this way. It has not and has escalated. I have consulted trainers and behaviorists. One (the trainer) says to use vinegar/water spray 50/50 along with a shake can, and yell "Leave It!" I have not tried this yet. What I HAVE tried is time outs. Warning, treating good response, time out for continuing to attack her. This could go on all day, and he is just getting sneakier about it. I have him on a lead whenever they are out of their crates together. Excercise does help with other behaviors, but not so much with this. Is the spray bottle and vinegar cruel? I am so beside myself, I want to love this dog. I do not give up on dogs. I have a lot of expererience having raised a GSD from pup to his passing, and he had temperment issues, bad hips, etc., and we stuck with him through a LOT of serious issues. This new pup however, is really really testing me. I am NOT hitting him, but he has been grabbed and smacked by my husband, not often though, and my husband knows this must stop, and is useless/dangerous. I am tired of him hurting my Uma-she's such a passive little girl, unless she's pushed. And SHE is quite tired of him. Their encounters are getting more violent.
Dr. Sarah,  (my vet's name by the way!) can you please offer me some advise?
Thank you so so much in advance!
Sincerely,
Sharon

Answer
Hello Sharon,

Sounds like you have a really active little guy on your hands, and he's going to keep doing this the other dog makes it clear the behaviour is not ok - and until he grows up a little more.

What you are describing is normal, but there are things you can do to help speed up his education of how he should behave around her, and other dogs.

You want to allow them to find their relationship, at the same time, you want to be sure no one is seriously hurt.  There are some things you can look at, such as:

How long do these battles last?
What happens if you do not break up the fight?
Is either dog in any imminent danger of injury?
Is there anything that seems to provoke the charging?
Does he visually fixate on her before he runs at her, or is it more just like he goes wild with playing and sneaking and biting?
Does he bite and run, i.e.  run away in the other direction after nipping the older dog?  
Does he bite her on her tummy or legs?
If you are playing with them together, with a ball, and the older dog gets the ball, does the puppy try to fight her for it?

These are all "puppy" behaviours. It gets better.

Sometimes it is just the way of dogs. It can be terrifying, especially if you have not seen dogs fight before. I am not an advocate of the "let them fight it out" method.  However, to some degree, they do need to see how much the other one will tolerate. And, for a puppy, the biting repeatedly, and charging is natural behaviour. Your other dogs response is natural behaviour.

There are things you can do to help speed along his learning process.

First off, I would not use vinegar and water - have you ever gotten vinegar in your eyes?

"Leave it", however, can be VERY useful, if you use it to stop the interaction before it starts.
This assumes he is successful with "Leave it" in general. You should work every day on the general "Leave it" so he learns that when you say "Leave it", he is to refocus his attention immediately preferable on you. Do this with objects, then food, and when he will "leave it" successfully, then start working on him with it with the other dog around.

You have to actually almost anticipate he's going to look at the older dog - and as he does it say "Leave it". Pull up on the lead at the same time. When he complies, you then say good dog, treat, etc.

Also, it sounds like he would benefit from puppy school. There, as he is around other dogs and more socialized with them, he will see what is acceptable, and see that he is not the only other dog in the world, that it is ok for there to be other dogs around - even enjoyable.

It sounds like the new dog is a wonderful dog except for this challenging, biting behaviour. It also sounds like you are trying all of the right things.

Hope this helps!