Hi there-I'm having problems signing in so I've had to post as a visitor, this may be a bit long so please  bear with me we rehomed a boxer bitch (not bred by us) at 2 1/2 years old as she was fighting with our other bitches she has lived a very happy life as an only dog with friends of ours they are a young family and for the last 3 years we have kept in touch and she was fine until 2 weeks ago when she snapped at their youngest son she has done this 3 times over the last 2 weeks and has grazed the little boy on his finger this last time, she has always lived with children and has never before shown any aggression to a person infact the child she has turned on has always been the one she has had a special bond with.

She is currently undergoing treatment for crystals in her Kidneys (a recent thing) but the vet can find no other reason for her to be aggressive medically - I am inclined to disagree - I think due to her kidneys or some other reason she is not feeling well and hence short tempered - does anyone have any similar experiences to draw on as I have never had a Boxer turn before For the moment I have advised them to keep her caged when she cannot be watched with the children to carry on with her kidney treatment and see if she returns to normal obviously the childs safety is the main concern but the family would be heartbroken to part with her any help would be appreciated. Thanks

I agree with you that her medical problems may have lead to this behaviour, another thing to bear in mind is that Boxers are one of the breeds with a pre disposition to Thyroid problems, which in turn can lead to aggressive behaviour.  I'd ask the vet for a full check on this dogs blood tests, and then ask for some one to one sessions with an APBC or UKRCB registered behaviourist.

Also what needs to be considered is that 3 year olds can be unkind to a pet.  Many dogs will accept a lot from a very young child but get less tolerant of this as the child gets older.

I have had my own neice admit after many years (about 15) that she used to tease my first dog, if my back was turned.  Small wonder that my bitch would come and seek my help and I would let her upstairs to get away from the kids for time out.

If she's been fine for the past 3 years it seems very likely that the kidney problem is affecting her temperament.
I think your advice to the owners is sound and, hopefully, things will get back to normal when the treatment is complete.  If they're watchful in the meantime there should be no need for difficult decisions.

I think you are right, humans report kidney stones as the most painful of all things :(