Early May? That's plenty of time to get new worms or cocci to come back. You might want to do a fecal just to be sure.
Oh yes hormones, stress, heat (higher internal temp+anxiety), etc.Something I've noticed since the days are getting shorter. When my does are in heat they have soft poop. Then once they aren't it's back to normal. So my thought is if hormones can change human poop why not goat poop?