About 2 weeks ago I noticed Lily was looking a little more lethargic than usual. I also was going through a very traumatic time in my personal life though and was finding it hard to get them out for the play time they are used to so i thought he might have just been mad at me. But I continued to observe him and ever since he has been coming out for some play time and then going back to his cage and sleeping the rest of the time. It's not to the extreme cuz he is a pretty lazy boy to start with. I also noticed that he sometimes has a clear discharge coming from his nose but not all the time. It's not gunky or super unhealthy and I know the vet has said that as long as it's clear it's not really a problem so I'm not too worried about that but it's unusual for him and he has also been sneezing a lot. So I know he has some kind of cold/upper respiratory infection for about the past couple weeks but it hasn't progressively gotten worse. His coat still looks pretty shiny too. He just seems more tired than usual and the minor cold issues I mentioned. My other rat Daisy has chronic mycoplasm issues so he sneezes constantly. That's just how he's been since the day I got him. I have had one incident with him getting very sick and having to do antibiotics and the vet gave me two rounds of antibiotics so I would have an extra round on hand in case Daisy would flare up again sometime or if Lily would come down with it too. So I do have the antibiotics so that I wouldn't have to actually take him into the vet and I am aware of what it is like when they are sick because of my experience with Daisy. My question that I would love your opinions on is do you think I should treat him with the antibiotics now or should I continue to wait until it gets to the point where it seems serious? Cuz like I said I can tell he is sick but it seems mild. And it has continued for 2 weeks, so I'm not sure if that is something that can go away on it's own or not? What do you guys think?