I am very concerned about my 12 year old min pin .She has congenital heart disease and as of 2 days ago quit eating, but is still drinking water,and chasing my other dog off her food dish.I can not afford to take her to the vets for a bunch of tests again.

I had a min pin with liver damage and she didn't eat... we had to feed her our food just so she would eat something. Our dog eventually died from it 1 day after the vet said shhe would be OK

When my 12 year old Lab ignored her breakfast one morning, I took her to the vet that day. It only took the vet a few minutes to find the problem and send me home with the medicine that had her eating the next day. Two years later she is doing fine, walking a couple of miles for a swim some days.

Your dog's problem could be something simple to find and treat. If instead, you work at tempting it with rich food, it could die suddenly. 12 shouldn't be that old for a Min Pin.