Not sure about the dwarf situation, but if you have a low cost spay/neuter or a free spay & neuter to low income family or highly populated area it could be humane to use their services versus the innocent cats populating & being left to be killed alive by coyotes. Just a thought....
Diarrhea that is not controlled will eventually lead the kitty into dehydration mode, which then if left untreated leads into organ failure. Just like in humans.
Speak with vet about how a gastroenterologist can help. Maybe have an ultrasound done. Maybe also changing the cats diet to a food...
