Case of the man boobs

Ive noticed the past two weeks Ries has been NQR when I walk him out of his stall. However, every ride he has been sound. Thursday, he had other plans.

This happened (much worse) last year, where his chest/armpit gets swollen and he is lame. Last year I treated this with bute and linament.

I sat in a jump saddle for the first time in forever, and while expecting it to be weird, this felt wrong. He had minor swelling in his chest again but was really loose in his chest and shoulder when I stretched. I hand walked him, gave him two grams of bute and tucked him in for the night. 

Yesterday he was sound, but still NQR. He trotted out beautifully in hand but I opted again for just a long hand walk session. Spring Vaccs are around the corner (next week) so my plan is to be cautious and see what the vet reccomends. So bizarre.