My sixteen month old yorkie is doing this too. I started to take him to the vet on Wednesday because of it and he wouldn't eat either, but I read on here that plain white rice and plain boiled chicken was good for an upset stomach so I fixed that for him and he gobbled it up! He wouldn't touch his other food. I gave it to him again yesterday and he ate it and he's feeling better since he's eating the chicken and rice and he's more spunky but he's still got diareha and not 100% himself. I haven't seen him throw up since he's eating again but I'm not sure since I don't see him every second. I'm taking him to the vet this morning.
I would try the chicken and rice (I got that advice on here
) and see if he eats it and take him to the vet as soon as you can.