Glad you found the cause and thanks for the heads up with Claritin.
It seems to be annual bluegrass that's bugging him.
We had a week of rain and it all germinated, bloomed and went to seed. As soon as hubby mowed it all off, things have settled down on gunners belly!
I went across the street to the neighbors with him, their yard it's behind ours in this growing process though! Guess who's belly broke out again?! Lol
we have also found Claritin works much better for him than benadryl!
I goggled Claritin for dogs, lolgreat news.... what is the Claritin dosage?