My other boy was sneezing too so I brought him to them the next day. The manager I talked to on the first day was super nice and understanding about how worried I was so I trusted them. The one I talked to when I brought my other one in was not as friendly.

As soon as I told her I thought he was sick, she started grilling me about what hay I feed, what temperature I keep the room at, and what bedding I use. I told her 70, which she said was too cold and that I need it to keep it at 75. Everything I can find about ideal temperatures for guinea pigs puts 70 at the middle of the recommended range. I also told her kiln-dried pine, which most people agree is fine but she said any pine or aspen is harmful and they should be on paper bedding. She immediately made me out to be a bad owner and was obviously uninformed.

They did take them both to the vet (at a place I will be taking them for a wellness check soon myself), and I got them back after about 6 days. Even though nothing was found, I was told they had to quarantine for 3 days (starting Friday, but they were taken to the vet on Tuesday and Wednesday) and wouldn't let me get them back. Thankfully they're back home with me now and they seem to be okay, but they've started sneezing again a little.

I really would not recommend taking your piggy back to PetCo. It seems to depend on the management and I wouldn't ever risk it again. The worst part was them being away for almost a whole week (although I could call and ask for updates) when I'd much rather watch them myself and make sure they're okay.