I picked up my 6 month old bully earlier and noticed these large welts that covered his entire belly. Does anyone have any idea what this could be? He hasnt changed anything that has to do with bedding..its washed in Dreft and he has never had issues with that.. He has recently been on prescription diet so I dont think it is a food allergy. I am transitioning him to Purina Pro Plan via my vets advice.. but it has not caused skin issues and he has been on it for around 2-3 weeks. Does not seem to be itchy.. Does anyone know anything about this?