Also if they are all housed together inthe same cage, the whole colony will be infected if it is a respiratory thing, they are very contagious especially SDA, but like I said it would just be a Myco flareup. I would suggest handling them while they are sick and you don't have to worry about touching the others if they are all inthe same cage. A sick ratty needs lots of love and some of the time this is the only thing that can pull them out of it.

If they are senior citizens and the Baytril isn't working ask your vet for a dose of Gentocin. It is an injectable and fast acting antiboitic. Or you can try Tylan which is also a great broad spectrum antibiotic. But keep in mind as everyone is saying, this is not your fault. Rats get sick and that's just something that happens.

Carefresh is used as cat litter, it is also a very safe bedding though. It is made out of recycled paper and not too dusty, however it is expensive. It is a very cozy bedding for small animals and I like to mix it with my pellets so that they have much more softness. I also throw some into their hidey beds.