Can you go to another vet? I see that you are in The USA so there should be another vetm hopefully more knledgeable bout rats that you can tajke ther to see.
Rats become ill and die fast so she needs to see a vet asap!!
and hopefully be given baytril + azithromycin ...... orally, twice a day ... for at 6 weeks if they help.. Azithromycin can be purchased from a pharmacy with a prescription from the vet, but is not very effective if not given with baytril. Baytril is a main vet antibiotic given to many species of animals
http://ratguide.com/meds/antimicrobial_agents/enrofloxacin_baytril.phphttp://ratguide.com/meds/antimicrobial_agents/azithromycin.php