Sneezy Rats

Reno & Rusty have come down with the sneezies since (I think) two days ago...I'm so scared that they might be sick. Rats are notorious for getting really bad respiratory infections. I just hope it isn't that and it's just the dusty bedding (which I took out) or the pollen in the air. We do keep our windows open sometimes. They sneeze consistently and only when they are active. But that's all there is- there's no other symptoms. They eat, drink, are playful and mischievous. But I feel like I'm analyzing them so much now that they started sneezing and it's making me think that they are more lethargic than they actually are. I don't know. I just hope my babies are okay.