Just last weekend my 6 year old stopped eating and drinking for two days. she did however have diarrhea. we took her to the vet after the second day and it turned out she did have an infection. the way they found it was via blood test, i also gave them a go to test her stool. she was hooked to an IV for two days and on day one with the fluids and antibiotics she started eating again. the vet also gave us some cans of food that are suppose to be very tempting for dogs
maggie just loves it! its not meant to be a permanent diet but it definitely helped her start eating. maybe you can ask about that to help with the appetite. these dogs are so small you have to be very careful about not eating or drinking. they dont have much weight to lose.