Chloe is one of those dogs that gets overstimulated in play, and then resorts to being VERY physical. I used to be able to have structured rough housing with her, but the past few times I've been at the house and played with her I've had to stop due to her getting wound up to the point I'm afraid I'm going to end up with a nasty bite. Always before I could tell she was in control of herself; I might get nipped hard, but it was still all in play. This past time it wasn't play, but borderline outright aggression where if she was going to bite, it would have been for real. So from now on, playtime with her is completely structured. Fetch with a little bit of tug slipped in, but she has to perform commands while we're playing. (I say "sit", she sits, I throw toy, she gets toy and brings toy back, we play tug with toy for a few seconds, I say "drop it", she drops it, I say "down", she downs, I throw toy...) She has fun and enjoys what we're doing, but it stays "low key" for her and she doesn't get over stimulated.
She's also not the kind of dog I would ever take to a dog park, because she does the same thing with other dogs. What starts out as play quickly turns in to something more and she gives only very subtle, quick warning signs before what was fun turns into something serious.
She's also a dog I had to get used to being handled. She has arthritis in her right back hip so she is very sensitive there and WILL bite if you hit her/bump her/pull on that leg. But for everything else, I would do X and then cram cat food in her face. Took her awhile, but she's much better about structured handling now and I can restrain her/groom her/etc. I still have to be very careful about the situation she is being handled in and her current mood, and I would definitely still I still manage her regarding her intolerance, but she's much better.
