Welcome to the board, Cherie!
Since this is such an old thread, and since your dog has other complications (I see you list pancreatitis in your profile, and you've mentioned the joint problem), you may get more replies if you start a new thread just for your dog.
The infection may well take 4-5 weeks to resolve. We had a bout with folliculitis, which is a deep infection of the hair follicles, and it took at least 4 weeks... The infection in your dog is different, but it isn't unreasonable to think that it would take weeks to resolve.
Are the joint problems new? Just since you started treating the infection? Or are they ongoing? How old is your dog? If you start a new thread, putting this information in the first post will make for quicker responses!
There are a number of supplements, such as glucosamine/chondroitin/MSM that can help with joint problems. Also omega-3s and -6s can help boost immune systems. But, if your dog is prone to or has pancreatitis, remember to run any supplements by your vet first--especially any fatty or oily ones--to make sure they are safe for your dog!
Good luck with your girl, Cherie!