Answer

With this breed it might be she is having a pancreatic inflammation issue. You can read about this here
http://www.peteducation.com/article.cfm?cls=2&cat=1580&articleid=335
As this has been going on for so long she may be getting dehydrated so I'd plan a vet visit to get her help.
It might just be she has an intestinal parasite such as giardia or coccidia and the vet can check for those too.
They can give her an injection of stomach calming meds if needed and fluids of course too.
So seeing the vet to find out what is going on should be a priority.
In the meantime you can see if some bland food and plain pedialyte added to her water bowl will help her.
I would suggest trying boiled chicken meat or hamburger with the fat drained off, mixed with really well cooked rice in a ratio of 1/3 meat to 2/3 rice to see if that works. Or you can try a jar of baby food meat such as chicken or turkey or beef. It's not a balanced diet but OK to use for a few meals while working on controlling digestive upset.
Hope this helps you!

Expert:	NancyH
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Answered:	11/29/2007

Dog Expert:Rescue, Train,Breed,Care

30+ yrs dog home vet care & nursing, rescue, behavior&training, responsible show breeding, genetics