incision opening, possible seroma drained itself

Question
Hi,
I have two rats and one of them had a tumor removed last week. She seemed to be healing well, then last night I noticed what I am now pretty sure (after internet research) was a seroma. This was late at night and I didn't know what it was, but figured I'd talk to the vet in the morning.
This morning when I was holding her, I noticed that the incision was starting to open up a bit at one end (no stitches per se were used...I don't know what the technical term is, but it's like the incision was glued together basically. so there was nothing for her to pick out, but I guess she's been licking at it and so forth when I wasn't watching) which I was obviously concerned about. Then all of a sudden I smelled something which I can only describe as what I think bottled, concentrated nursing home would smell like, and I realized that her wound had drained onto my shirt and pants.
I immediately put her on a clean cloth on a chair while I changed out their bedding so I could put her back in, but she was licking at the wound...she didn't seem to be distressed about it, just really trying to clean the annoying itchy spot.
The fluid that drained out was clearish, possibly with a slight yellow tint, but there was no red in it and I'm sure blood wasn't involved.
I emailed the vet in the morning and no one got back to me; I called this afternoon as soon as I could get to a phone and they basically just refused to tell me anything other than that I had to go to the emergency vet (the vet who can do rats isn't in on Mondays and I honestly think she would've given me a better answer than that), which I can't do because of lack of transportation, and Catherine didn't seem to be faring any worse several hours after the fluid drained.
So I started doing more internet research and I came across this http://www.ratfanclub.org/surgery.html (sorry for putting a link in the middle of my question). So, I would like to do what she recommends under number 12, but I am concerned about closing up a wound if it is already infected. If you have any recommendations I'd very much like to hear them; the opening is much less than two inches across.
I'm also wondering if you know of any safe over the counter antibiotics that would be useful and work for a rat.

Thanks very much!

--Ilse
and Catherine and Mara

Answer
Leave it open. It will drain and heal on its own if its just a seroma.

You can check out my site, sandyscrittercity.com and refer to the page on surgery complications. I have a piece I wrote on incisions opening up etc....  
I am going to assume a mammary tumor was removed and surgical glue was used to close, possibly sutures were under the skin which is why you did not see them.  The good news is, if it is a mammary tumor that was removed, they are non invasive. Its almost like peeling a little growth off of a potato, just superficial to an extent. If it opens, you may see tissue, maybe muscle, but never will you see internal organs like some people fear.  The skin is a remarkable organ and rats that are healthy and under no unusual stress heal very quickly. I would refrain using antibiotics unless there is active infection. There are no safe over the counter antibiotics that can be used. Its all a rip off anyhow, the stuff you may see in pet stores etc....non of them are even near potent enough to do the job anyhow.
If it gets red, crusty, has an odor or discharge that is green, yellow or thick white, thats a different story and the vet should take a look at her.