wrorryed sick

hi my god is 13  mixed labrador 3 weeks ago had he it the vet because he was snoring all the time and when he was awake they put him on piils antibiotic for 2 weeks for a respiratory  airways infection vet said if it had not cleared up after the pills said come back and they were going to talk about doing some tests ,, he was a week off the pills yesterday and he start vomiting all day yesterday i went back to that vet but there were not there my dog has had some food and keep it down but wont drink for me at all can anyone help me should a be worryed or could it be a bug or something he has never been unwell befor we have he 12 half years ,, thank you

[TwoBitsMom]

You tried to do the right thing yesterday by bringing him back to the vet.
It sounds like your dog needs to be re-evaluated.  It is possible that the initial infection did not clear up completely, and he will need more antibiotics. It is also possible that something else may be wrong.
Follow your Vets recommendation for further tests.......any dog that is 13 should have some blood work done. It is something you should request every year.
Get him back in to see the vet, as soon as you can.
Connie