My four year old Springer bitch has started walking about with her mouth open, showing everyone her bottom teeth.  We're going to the vet tomorrow cos I'm worried that she might have something wrong with either her breathing or her mouth but she accepts me feeling her jaw.  She might be having a little more trouble than usual eating her biscuits but her appetite is fine and she is still running around killing things.  Can anyone suggest why she might have started this?  One nostril seems more closed that the other.  I used a headcollar on her Saturday and Sunday...

Have you seen her shut it at all ? if not id guess shes unhinged one side of her jaw , id get her checked out soon as you can.

She shuts it when she's lying down. We went to the vet today who said it could be one of two things.  He said it was typical in dogs that carried objects too large or too heavy for their mouths and to lay off letting her play with tennis balls and frisbees etc to give her mouth a rest. She has been playing for polo balls and likes to try and lift logs.  If it's not that, although too young (hopefully), it could be a degenerative neurological thing and will pull her head about all over the place and affect her eyes.  I hope to God it's not that.  Still don't understand why she's panting so much unless it's just that she's relying on her mouth to breathe, not her nose.