My 15 year old yorkiepoo has quit eating. I have to hand feed her with lots of coaxing to get her to eat anything at all. She's never been a big eater but now its nothing. She's had a history of heath problems, back surgery at 3, cervical surgery at 7, pancreatitis, colitis, crystal urea, fluid in her lungs, enlarged heart and now irregular heartbeat. I started her on senior vitamins about 1 1/2 months ago and vitamin B12 (1/2 pill) 3 days ago. So far it hasn't helped. Any information you can provide would be appreciated.