Why does my dog smell sweet?

I've recently found a pitbull dog. It is obvious that she has a home other than mine now. Since nobody has responded to my postings she has been staying with me. I put her away in the bathroom when I leave. Since I have met her she has had a different smell to her. She smells very sweet. Almost like a cigar. I am worried that it has to do with an illness. I do not have the money to take her to the vet right away nor do I know if I will get a phone call regarding her 'real' home. Why would this dog have a sweet scent to her? She is a sweetie!