It happened within a few hours now there are so many, they are bumps underneath the skin about the size of a small ball you get from child toy dispensers.We have 2 4 month old pibulls, one has it, and the other one doesnt. Also, it started snowing today, i was wondering if that had anything to do with it? They also have a bad habit of eating things off of the ground, maybe one might have ate mushrooms, but i'd like to rule that out and think of anything else it could possibly be. We live in the mountains so you can imagine the weather and surrounding ares. Any help would be greatly appreciated. Thanks.