i have a welfare newfoundland bitch between 4-8years, she came to our home in very poor condition and is now very fit and well and really loving.  She has always been bossy to our chill bill 2 year newf over toys food ect. she has now gone for our king charles for no apparent reason and wants to kill this was only in the house.  she now has started to go for him out walking and the king charles is terrified and spends most of the day upstairs.  we know we are making matters worse in the evening putting her behind the stair gate but we cannot exclude to charlie all the time. they have all been nuetured we have had her 6 months and she has only just started getting this bad recently   

My worry would be that she has a health issue, and the smaller dog running about getting in her face is making her grumpy.  I would be thinking painful joint problems with such a big dog and her poor start and care in earlier life.

Can you elaborate in which circumstances she has been aggressive to him?  Has it really only just stared or has tension built up over something gradually?

Sounds strange that she is all of a sudden now being aggressive and has been fine before, my guess would also be medivcal problem or maybe she just isnt a dog who like little ones jumping in her face all the time.

But my guess would be medical.

So your adult Newfie is bossy with your 2 year Newfie and now is not just bossy but vicious to your Cav Charlie, can I ask the age of Charlie?

If Charlie is an adult I doubt it is due to the bitch being aggitated by your Cav's in the face behaviour as older Cav's IME are usually laid back, not jumping and irratating to annoy the Newfie.

If health is ruled out, I would say her behaviour at the 6 month mark is due to her now feeling completely settled and at home and is showing her true character.  She does not appear to have any patience with other dogs, if neither dog is being bouncy or irritating towards her they are probably in quite a precarious position.

Do you know anything of her background, was she from a puppyfarm, shut away and not used to other dogs?  Was she attacked by other dogs? Does she have any kind of history you know of?

I feel very sorry for Charlie, poor dog having to live upstairs for fear of your bitch, I wouldn't have that, the aggressor would be in isolation not the victim, she would be segregated anytime she showed unfavourable behaviour.

Firstly, get that medical check, secondly segregate the aggressor not the victim, thirdly get in a behaviourist, but most importantly get to the bottom of her history.  See how things go, but personally my dogs of good character would always come before an aggressor especially a new arrival, I know you have done a good job in bringing her back to health but perhaps she is just not meant to share a home with other dogs. :-(

Agree with Carrington, not all dogs want to share their homes with other dogs. I also feel very sorry for poor Charlie, it must be very distressing when a dog that size takes a dislike to him, he must be living in fear. Not good for either dog.

hmm sounds like.. the dog is taking over the house, territorial aggression ? it starts with the small dog and then the dog  could work its way up the pecking order. do you think you are pack leader?   take all the toys up and put them in a box, only gets toys out when you are there to supervise. you need to exercise then discipline then affection, show no affection to the aggressor,  this will only reinforce the bad behaviour. seperating does not solve the problem only sweeps it under the carpet. Put the lead on the bad boy and then when he goes for the small dog Yank the lead say NO! show that dog whos Pack leader and then set some boundaries, dont shut the small dog out.

DW, Do you like Cesar milan by any chance?

i agree carrington.

although its not what you want to hear maybe another home without other dogs would be more suitable if she doesnt start to calm down or god forbid gets wrose.
after all its best she gets a forever home rather then you try and fail and she ends up going to a new home later on.

Anyway all the best luck and i hope all goes well

dexter :)

I'm sure that the key to all this is your statement that she has been with you for six months. I've had several dogs that have come to me as adults, and without exception they haven't shown their true character until they have been with me for at least six months. This has held true whether they have been the sweetest animals or little so-and-so's.

It sounds as though you have done a great job getting this bitch back into good condition, but unless you know her whole history and can maybe pinpoint where the problem might have originated, I think you have to consider very carefully whether she can continue to live in your family. Not only does it sound as though she could actually kill Charlie (and you would never forgive yourself if that were to happen) but what if she then turns on your other Newf? A serious fight between two dogs of that size would be horrendous, and you could be very badly injured whilst trying to separate them.

If she can't be found a home as a single dog with an experienced owner then maybe you will have to consider the only other alternative - sad as that might be.