Since you are looking for Dr. Stack I imagine you've already seen these, but for anyone else who hasn't, here is a link to Dr. Stack's articles online. There is one specifically on LS:
http://greythealth.com/lumbosacral.htm
And this one summarizes what drugs are OK to use in combination (and which are not - see table at bottom of article):
http://greythealth.com/pain.htm
See a good holistic vet. I have Rickie off NSAIDs completely now, using a combination of Wobenzym and Zeel. His arthritis is from age and changes in gate due to surgeries, so your experience may be different, but this may be worth looking into.
Unfortunately, lots. We have a daily treatment regimen here which consists of:
- clean the area with witch hazel on a cotton swab (real cotton - I buy those big rolls at the drugstore)
- dry off well with a tissue
- apply Unda 270 cream (available at many health food stores)
If it's really bad, instead of the Unda I apply Fusiderm (prescription from your vet) which is a combination of antibiotic and steroid - it really works but I stop as soon as I can because of the skin-thinning actions of the steroid.
There are several threads about this sort of thing in Health and Medical (some may have been pruned) if you do a search for "vulva".
Good luck with your girl.