Hi, Katie! Welcome to the forum. I was hospitalized for chemoembolization (liver cancer treatment) from yesterday morning until this afternoon, and am not feeling very well, but wanted to welcome you and give you some input.
My alcohol experience was much like your dad's, with the last 10 years before I stopped for good, being the heaviest. I drank mostly wine, though, or mixed drinks. I quit drinking when I was 43. I will have 25 years of continuous sobriety on Aug. 1st. But first, I had gone the hard drug route, including 18 months in the late 60s where I did IV drugs. Unfortunately, I contracted hep C when I was using...was diagnosed with it in '93 when I became fatigued. Had I not contracted hep C, I think I would have been okay. The first biopsy I had when diagnosed with hep C showed no cirrhosis. One done in '07 showed that I did have Grade 3, Stage 3-4 cirrhosis. Prior to that, in '05, I was diagnosed with hepatocellular carcinoma (HCC...liver cancer.) That was treated and removed, as well as the entire right lobe of the liver. The cirrhosis and liver cancer were due to untreated hep C. I tried Interferon (the only drug available at the time of my diagnosis), but couldn't handle it.
I did fairly well for a month short of 4 years, when I found I had a new HCC. I went into the hospital yesterday AM for treatment and was discharged home this afternoon. I expect to be listed for transplant today or tomorrow.
So I do think that your husband has a fighting chance of living much longer if he quits drinking entirely "one day at a time," which will add up to many days and years, if he has no other type of liver disease besides ALD (Alcoholic Liver Disease.}
He does need to go to AA. A form needs to be made up listing the date, time, type of meeting (open Discussion, Closed Discussion, Step Meeting, Speaker Meeting, 12-Step Meeting, etc.) and where it was held. There should also be a line for the Chairman's signature (or first name and initial of last name.) That is what is considered documented. If he drank every day, then he should preferably go to a meeting every day, or at least 5-6 x a week. Sometimes a transplant center will indicate how many hours in a month or times in a week the patient should attend meetings. This should be done prior to, or along with, the transplant evaluation appts. At Mayo, evaluation was a grueling process for me, with appts. 4 days a week for most of each day, the first 2 weeks. They kept adding things, and the treatment done yesterday finally finished it. I believe that was the 32nd appt. in 2 months. And I have to go back on Mon. for blood work and to meet with my transplant coordinator. Other transplant centers do not seem so thorough.
Has your dad had a liver biopsy? That is the gold standard for diagnosing liver disease and grade/stage of cirrhosis.
Lactulose is generally prescribed for hepatic encephalopathy, which includes confusion, personality changes (such as being verbally abusive) and sleeping for extended periods of time. Sometimes, Xifaxan is also given with Lactulose, though it is very expensive. Which brings up another question: Does he have medical nsurance? I can't imagine that he is working.
If he's not already receiving SSI/Medicaid or SSD/Medicare, someone should help him apply. Call the toll free number and ask for an application for your father:
1-800-772-1213
Or make an appt. with your local Social Security office.
I agree with Emma and others that you should check out the Hepatitis Resources folder, and there is much information contained in it about liver disease in general.
And now I need a nap. 
Hugs,
Connie