u/Pluto-plutonium

I’ve had my piggy for almost 2 years now. I think I’m beginning to develop an allergy to Timothy hay. I keep waking up congested and coughing when I’m in the room with him. The hay that I currently feed him is the oxbow Timothy hay and Orchard glass blend. What are the risks of switching him to strictly orchard grass? I worry about his temperament changing if I switch his food.
Pumpkin (my guinea pig) means the absolute world to me but it’s gotten to the point where I am sacrificing my own health by feeding him Timothy hay. I truly just want what’s best for him and I’m super nervous about potentially changing his diet.