I'm so glad that he's doing better! Cara, our first Pyr, had a bad reaction to a flea/biting fly spray with pyrethrins in it years ago, so we never used or allowed groomer's to use any flea product on her again that contained pyrethrins. In fact, we avoid them like the plague with all of our pets now. I'm just really leary of all these chemicals that humans & pets are exposed to now. We're fortunate that we don't have a problem here with ticks or heartworm, but fleas pop up (ha!) occasionally, so we have to deal with them sometimes but w/o pyrethrins. Do you know what the active ingredient is in Biospot, just out of curiousity and so that you can avoid them with him again? Also, you might want to add a cup or two of water to his food for the next few days to help his body flush out the toxins (and b/c he may not have drunk enough while he was feeling so lousy). I've done that with my pups when they haven't felt well & it seems to help perk them back up sooner. I kind of think of it like encouraging your children to drink lots of water & juice when they're sick.
Again, I'm very glad that he's doing better!