Sorry to hear you lost a rat. How long did you have them before the one died?

I have 6 in QT right now and I'm just watching for any sign of illness. One of the 6 is from my established colony and was put in with a new male just to keep him company and I figured I let her have a little or 2 to feed off. I plan on keeping them all in QT for about 60 days.

Funny thing is during my observation the female from my established colony seems to be sneezing a lot but she doesn't have a runny nose nor labored breathing.