Wow, 17 years old, you
have done a wonderful job keeping a dog
healthy for that length of time, regardless of what breed it is.
Bland seems to be the only thing I can
suggest, and hope you
are not feeding one of the "popular" dog
foods seen on most super market dog
food shelves. No grain is one suggestion.
Did the vet say anything about using one of the human diarrhea over-the-counter medications?