I've been thinking this is 'puppy' behaviour but it's getting a bit old now...my setter is 5 months old, is house trained like my other dogs, but  whenever we get igsn when she hasn't seen us (be it for half an hour and we might not have even left the house) she pees herself a little. Not a full blown toilet visit but enough to make a mess.  I've never had any other animal do this in my life and it's blatently like she's overexcited.  She doesn't jump up and down, bark or go mental, she just wags her tail like mad and squats down slightly and pees a little. Anyone else experienced this, or anyone got any ideas on how to train it out of her?  Even when I ignore her it improves things but sometimes she still does it.  The rest of the time she goes to the toilet in the correct place so not entirely sure how to tackle this one, as the other dogs have never done it :-s

You're right to say it's excitement, and as it's completely out of her control you mustn't chastise her for it. Simply make sure you greet her on a surface where it doesn't matter, and she'll grow out of it. My old labrador was about a year old by the time she was 100% for this, although she'd been housetrained from 10 weeks of age.

If it's possible, don't actually greet her at all: just ignore her, no touching and no eye contact but simply call her to come outside with you.  She'll probably pee outside anyway once she gets her paws on grass, then you can call her to you to greet her properly if you wish. 

I used to do this with my youngest partly because he had over enthusiastic greeting behaviours and also because I didn't want him to be able to tell the difference between me going shopping for 2 hours or being in another room for 20 minutes.  At 18 months it's a different story but he still quite quickly heads to the back door as soon as we get in and we still avoid hellos and goodbyes with both dogs.