I have a friend in Canada that has an older dog that recently developed fistula. The Vet gave her metronidazole and an ointment ....and the dog is not improving at all. She is a bit isolated and has no internet.....and hoped I would know someone that has experience with this. I don't. Is this the current treatment for this problem? Any advice for her? Carolyn marhaven@xxxxxxxxxxxxxx www.marhaven.com