peeing due to stress?

I've been peed on for nail trims more times than I can count. It's definitely stress related. Emma is an excited peer. She'll occasionally pee at the vet's office, or if she gets startled over something. She was really bad about it, as a puppy.  

If he has been doing so much better with housetraining I would chalk this one up to fear or stress.  My chow loses control of ALL his bodily functions when strangers try to trim his nails. My vet has a theory that this is a defensive reaction much like a skunk to make people back off and leave him alone. 

 Yes! Peeing is what most trainers call a displacement behavior. They are feeling pressure or stress, and will pee to relieve that. Other stress related behaviors are sniffing, yawning, avoiding eye contact, etc.

When our herding trainer put too much pressure on Neiko, he would walk off and go pee on something. Or he would go sniff around, ignoring the trainer...along with a few other things. 

Ok, so it sounds like what I thought was right.  He hasn't done it since so thankfully it does not appear to be a housetraining setback.  I think I'll take him back to the groomer for nail trims from now on!