Oh dear, it's like they say..."be careful what you wish for".......the little Yorkie that was lost and found by acquaintances I just picked up awhile ago. He's extremely cute and very very sweet. He's also very hyper, which Max is not

. I'm not sure what to do right now. He hasn't been neutered and he's chasing Max constantly and has started trying his best to hump him. I think it's upset Max to the point that he's starting to vomit clear fluid. Max was perfectly find before I got this little guy home.
As I'm sitting in the chair at the computer, I have Max on the desk to keep him away from the new guy and the new guy is trying his best to jump up here to get to Max (he's also very vocal...not barking, just "talking". If I put him on my lap, he constantly tries to get to Max.
How should I handle this? I really need to go to the store to get the little guy some food, as he's pretty thin, and Max has only diet food. I'm afraid to contain the new guy b/c he scratches on the door and this isn't our house, and if I let him run around, he "marks" everything! HELP! This is the guy I'm hoping belongs to someone else, but she won't be home til after 6 pm and then I'll email her some pics of him. Now I'm REALLY hoping he's hers, LOL. What have I done????