Well tonight I found out why. It happened again as I was petting him on the couch. I don't know if I was looking in a different light but his lower jaw seems very slightly misshapen. So he had to tolerate me prodding around, which he didn't very well. There is some kind of mass there. It's not tumor like, it reminds me of scar tissue, it's pretty hard. And now it's very obvious to me why he doesn't like to be touched there, it's obviously painful for him. I feel like crap for not putting it together until now

We are obviously going in to have it checked out but if you guys could spare any extra good thoughts, we'd appreciate it. I know nothing of what this could be but because of his mast cell tumor diagnosis, I'm pretty worried.