URI treatment

Question
My guinea pig has been ill for almost a month with a URI. A day before her symptoms appeared, we had a dog in the house. I have heard of guinea pigs contracting Bordatella, and if they do that it is always fatal...I took her to the vet and she is now on Baytril, Doxyxyline, and Reglan. The vet also gave me crtitical care force feedings. She's not wheezing anymore and her nose is not runny but her work of breathing still hasn't improved. (It's been 5 days since we started treatment) Her whole body shakes with each breath and she refuses to eat her pellets. She will take a few bites of grass or broccoli now and then, but definitely not like she used to. It has become almost impossible to give her the medicine. She squirms and bites and kicks (even though I wrap her in a towel) She has taken meds before and not had this problem. I'm starting to feel like it would be more humane to stop treatment (which seems more like torture at this point) and let nature take it's course. What do you suggest?

Answer
She is on as much treatment as she can get with the medication, so if she is not getting better at all, which she should have by now, it may just be better to let her run it out or euthanize her if it just seems cruel to let her suffer if she is. She might get better faster with trimethoprim sulphonamide as the antibiotic along with 1/4 tsp Robutussin DM cough syrup a day, then Vicks vapor rub on her nose, if you'd like to call her vet and switch treatment you might want to try that first. It does take a little while for antibiotics to work, usually a week, but cough syrup and Vicks should work immediatly. If you feel like it is better in her case to put her to sleep though, that may be the right option, if she looks like she has given up then there is no use in trying to save her because if she doesn't want to live then no antibiotic will help. It is really up to you in interpreting what she feels. Let me know if you have any more questions.
Brittany