my ill dog

my dog was not eating food within 5 days but i notic that he was drink some water but he had vomating before drinking water

[Margot49]

It would be difficult to even speculate what the problem might be.  After that length of time without eating and vomiting, a visit to the Vet should probably be done and soon.
Try cooking up some chicken and rice (no skin) and see if he might eat some small meals of that but it sounds like he should be checked.

[Dakota2012]

Have vet check pancreas levels. I have a pom that those were the symptoms when her pancreas would flare until we got her on correct food. Best of luck.