My brother got a puppy yesterday, and my dog (he's about 4-5) was ok with her yesterday, but today he keeps growling at her every time she goes near him, even if im not near him (hes a mummies boy)
She is smaller than him, hes only a small dog himself, but she is going to get a lot bigger being a coolie x mastiff.
What can i do to help him get used to her and to stop being such a grumpy bum?