Lump and Rat

Question
I have a rat that is just over 1 year old.  One week ago she developed a dime size lump on her lower belly area.  We thought it was a tumor but then the size decreased by 1/2 in about 4 days.  She still has 2 small size lumps next to each other and her nipples seem slightly enlarged.  What should be our next step.  Thanks

Answer
You will probably need to have them removed. Sounds like mammary tumors.  Please see my site, sandyscrittercity.com and refer to the topic on mammary tumors and tumors to see if this sounds like what I describe.  Do  you have a vet that is very good with rats and rat surgery?