Actually, I can't believe I had almost forgotten about the recent experience of my brother and sister-in-law
- perfect example:
Last year they rescued a male German Pointer (Roscoe)- approx. 2 1/2 yrs. old. Sweet, loving, goofy, well-mannered. Then about 6 months ago, they rescued a male Weimeraner (Shadow)- approx. same age and temperament and both were fixed. My sister-in-law was in Heaven- the two dogs seem to be buddies from the start- she had pictures from day one of them curled up together sleeping, following each other everywhere, etc.
A couple of MONTHS went by and things started to get a little disconcerting- she noticed the Pointer started growling at the Weimeraner for what seemed no apparent reason. When outside, Roscoe (Pointer) would obsessively follow Shadow and stand in almost a guard position in front of him not allowing him to use the restroom (which he would then come inside and pee- which would then cause Roscoe to pee in the house as well)- I was witness to the outdoor behavior one time- he would barely let Shadow move 2 feet across the lawn. Then they wound up having minor scuffles in the house... it then progressed to a bit of blood (I honestly can't remember who injured who- I just remember there was a vet visit)-they were then separated in different rooms at all times- it then progressed to where Shadow (the seemingly "picked on" one) started growling at and attempting to bite PEOPLE (was this a way of venting his frustration at his treatment by Roscoe or trying to assert some authority over someone???).
It finally came to a head one night when my husband was over at their house watching UFC with his brother. My husband was sitting on the floor w/ Shadow laying by his side (they had been buddies all night) and my husband got some potato chips. Shadow looked up at him and my husband said "No, you can't have any!" in a perfectly calm, playful voice (not scolding in any way, shape or form- both BIL and SIL were there) and Shadow lunged and bit him in the face (very mildly, THANK GOD, slight scratch and bruise, that's it) and my brother/sister-in-law then knew that they couldn't have this situation in the house anymore. They returned Shadow to the vet they rescued him from and Roscoe returned to his sweet, loving self. My SIL was heartbroken but knew this couldn't continue for the sake of either dog (and any people that came to the house- especially her daughter and our kids!).
Again- this was after a sweet, wonderful honeymoon period where they truly seemed the best of friends for a couple of MONTHS.