Aggressive Chesapeake Bay

by Lydia
(British Columbia)

I have a 4 year old spayed Female Chesapeake.

I got her at 4 months of age. At 1 year, I had a roommate who had a MN shep X husky of the same age and they loved and played with each other without ever any issues! We lived together just over a year and there were never any problems. (I know she was dominant and especially over food items). She also grew up with a cat.

A year ago (my dog is now 3) I had a new roommate move in. My chessy wanted to play with her new dog (same age and a FS). Her dog was dominant over her owner - so when ever my dog got in between the new dog and her, her dog would attack mine. Eventually, my dog started to fight back. We got training from a professional trainer to learn to help her dog.

NOW however, I suddenly my dog is unpredictively aggressive and will attack other dogs.

With the training, we are able to go for walks together with both our dogs. However, there has been a time that my dog out of the blue just went after my roommates dog. There are times when I can see it in her eyes and I call her and put her on a leash - but when I cant get her in time she goes after her dog.

Now I went to work with my dog and introducted her to a new dog (a little male mutt dog, WAY smaller then mine) and we went to introduce the dogs, both on leashes and they were just doing the butt sniffing thing and my dog just pounced on her dog - as she was leashed I was able to get her off...the little dog didn't do anything and was quiet submissive. Now we do keep the dogs apart but if she sees him she will grow at him.

There are a few other times that we are in the park and she is on a leash that she grows at dogs that come up to say 'hi' I don't want to pull her away so she senses my fear, but I don't want to have to avoid every single dog.

I have gone to a off leash dog park before (this is before all the aggression) and she showed NO interest in playing with any of the dogs and just followed me.

I used to walk with a friend of mine who has a small poodle-malty cross....and we walked well together...this little dog always jumped and barked bitting at her ears..and then when I think she got tired of it actually put the dog down (no physical harm was done) to say she had enough. But normally the dogs are quiet fine together. one day my friend picked me up and I put my dog in the back of the van with her dog and within minutes there was a scuffle - again no damage done

I am thinking my dog has personal space issues - but I am not sure exactly how to deal with this issue. I have 2 other friends I go dog walking with where our dogs are off leash and there are NO problems. WHy is she aggressive to some and not all?? And how can I anticipate WHO she will be aggressive to? when it came to the little male dog, there was no sign that she would go after the dog - is there something more that goes on in dogs butt sniffing?

Thanks