So i talked to another vet. It is going to cost me a fortune to do all the tests she wants to do but i dont have another option. The vet says I have to wait 10 more days to allow the previous antibiotic to clear from the snake's system. After that she can make a culture and accuratlly test the bacteria for sensibility to different atibiotics. The vet also wants to take a X ray of the snake. I just hope the RI does not get worse before i can find the right antibiotic.

I guess the lesson here is always ask for a culture before giving a antibiotic.