Playing vs aggression

[Coconutter]

How do you tell when your dog is just playing and when he/she is starting to turn aggressive? Had a worry today - have had our rescue dog three months (she is 5) and she usually plays happily with other dogs. However, today she started chasing another (bigger) dog with her tail straight up, and she barked at her (which sounds normal but she's not a barky dog - goes mad if someone's at the door but has never barked at another dog).

I put her back on the lead straight away as I didn't want her to get aggressive - I'm still getting to know her really and she is a big, solid dog who would probably win against most others in a fight, and I obviously don't want even a hint of a situation like that! She is generally very calm (by far the calmest in her training class!) but has snapped at a couple of other dogs who got a bit rough with her and she can be slightly nervy of dogs bigger than her. How do I tell what is play and when it's time to put her back on the lead?

Oh - she has a tendency to bat other dogs with her paw while playing which can send them flying too...

Anyone...?

Tail up in the air is adrenalin. It could just be that she was over excited/aroused. If there's some boxer in her that could explain the batting. Having a snap telling of rough dogs is not aggression it's dog language. Have a google on calming signals. There are loads of brilliant articles and vids explaining what te different dog behaviours and actions mean. It could be that before she snapped she gave thm other warnings (going stil, silent growl, yawning, etc) and these dogs ignored it all.
The best option is to remove her from the situation calmly when it gets to excited and heated especially as your getting to know her. You'll never know exactly what makes some rescues tick as you don't know what things have occurred to shape their behaviours. After 3years I've learned that with my boy the best option for him is to avoid certain situations which he finds stressful. I'll never work him out totally.

Agree with aussie - the snapping you describe sounds exactly like she was disciplining the other dog. It's the best way for a young dog to learn polite behaviour and a sensible owner will thank you for it.

My dogs get barky / growly with certain other dogs, but it's a very different sound to the sound they make when the doorbell goes. It took me a while to learn the difference though.

I think you did the right thing - you were concerned so you removed your dog from the situation. If mine get too rough I always pull them out, even if they're only playing they are big dogs and I'd hate for them to accidentally hurt another dog.

One of my dogs will bark at another dog - just a single woof! - when he wants to play with them and they are not reciprocating. It means, Play with me! I wanna play now! Is that the kind of bark? To be honest I usually call him back at this point because it means he is over-excited and the next thing he does is go boing! boing! boing! in a totally crazy way.

An air snap is a sensible way of telling another dog to behave and back off.

I agree with Aussie and LettherebeCupcakes that you did the right thing as it's always sensible to remove a dog if you're not sure about the situation. It's also useful to practise calling a dog out of a play situation as they can get very engrossed, and sometimes you have to call them out (e.g. if the other dog owner isn't happy about it).

A friend's dog has a habit of batting other dogs when he plays with them. It sends small dogs flying. It's intended as play but can be too rough, depending on the size of the dog it's directed at. It's usually the prelude to a neck-biting game, which is still play but involves a lot of growly noises.