So I got took my sneezing guinea pig to the vet on Friday night and the exotic veterinarian told us she as a mild URI and prescribed her Bactrim for 10 days twice a day. She gave her the first dose on Friday night and I have been giving it to her since--morning and evening. However, I think she is getting worse than getting better. Her sneezing is more pronounced and I can see actual discharge in her nose and her breathing sounds like whistling. My mom is going to call the vet today, but when should I see improvements? I figured within 24-48 hours, but now I am worried. I know that bactrim is a weaker med and my parents (both with a medical background and knowledge) reassured me that bactrim will be fine, but I just want to help her to the best of my abilities. She is eating fine, drinking fine, is active and popcorns around, but she isn't getting better. The only other option I can think of is taking her to the vet and asking for Baytril, but she is only about two months old and I know that it could cause bone abnormalities but would it be better in the long run? I could really use all the help I can get because i'm new to this and I want to give her the best.