Pet rat - abscess

Question
I have two questions:  #1)  Our female rat, 9 months old, has a very large abcsess on her side and another inside her abdominal cavity.  We have taken her the vet twice to have it drained.  The last time, the vet told us there was very little hope for her because the abscess has taken over most of her body, and he was surprised she survived the surgery.  He prescribed and clavamox and enroflaxacin  but we haven't noticed any reduction in size of the abcsess.  Is there another antibiotic that you are aware of that would be more effective?

My second questions is: we recentlty got another rat about 6 weeks old that we were hoping to house with our other 3 rats who are about 9 months old--all female.  Two of the rats are fine with the new rat, but one of them is agressive towards her and has biten her. They seem to fine on neutral territory but each time I have tried to put her in or near the cage the one rat gets agressive. I don't want to subject the new rat to another bite but feel bad for her because she is alone.  Any advice?

Answer
Trimethoprim Sulfa is the best drug to use in this case. I would switch as soon as possible.   The bacteria found in abdominal abscesses are both gram negative and gram positive bacteria.  Although the other drugs can fight a broad spectrum of bacteria, Trimethoprim sulfa is the better choice when dealing with this type of abscess as it can better penetrate into the abscessed tissue to destroy the bacteria. Other meds cannot penetrate the  exudate such as thick fluids and pus, as well.

Can you please take some photos for me?  

The vet....what are his credentials?  Is the vet an exotic vet that is board certified or a regular vet in a general clinic that sees exotics on the side as well as dogs and cats etc...?    Why was there surgery done on an abscess? Can you tell me more about this?  Was the abscess inside of her body or did it start on the outside?

You can send photos to sandyscrittercity@yahoo.com


As for the housing of the rats....do you allow the aggressive rat to go into the new rats cage? If so, how does she act there?