Before I got my new Dobe pup 2 wks ago, I fostered dogs off and on and my 2 yr old Dobe wasnt thrilled at all the first few days. But with me showing her that it's not her decision to determine if the new dog is welcome or not she comes around. I have to take her territory from her and make her share it. She is smart enough and will get the idea.

But you do have to prepare for the worst. They do have a mind of their own and may go at it from time to time but if you are ready and see the signs of aggression or dominance you can easily stop it before a fight breaks out. And it will slowly train their mind that fighting is not allowed.

It doesnt matter what breed, size, or sex any dog can live with a new dog if you are committed to make it happen.

I get so tire of craigslist folks getting rid of a dog because their old dog didnt like them and they fight. Those are lazy, irresponsible owners who just think everything will be peachy with no effort involved. Good Luck!