I also was married to an alcoholic and agree with all of the above. If he never stopped dirnking beer, he never really got sober and pouring vodka down the PEG is pretty clearly alcoholic behavior.

You should definitely tell his doctor because there are many meds that interact very badly with alcohol or which drinking alcohol makes taking the med pointless (this is the case for many antibiotics for example).

As for him changing, as others have said, he has to want to do that himself. I personally found al-anon, which is a group for family members of alcoholics, very helpful to me in deicidng what boundaries I needed to set with my ex-husbands' drinking and, as you may have guessed from the fact he is my ex, eventually I decided just my presence was helping him avoid the effects of his drinking. But what you decide to do can be thought out much more clearly with the assistance of al-anon in my opinion--they will not tell you what you should do, just help you think about it in a productive way.

Nelie