n. A person addicted to milk.
1997
A 61-year-old man in Seattle who loves milk, and describes himself as a milkaholic, had a minor stroke a few years ago, and he has now filed a federal lawsuit against the supermarket chain where he bought most of his milk over the years and the Dairy Farmers Association of Washington for their failure to put warning labels on the milk cartons.
1987
Norton is an admitted "milkaholic." "That’s the one thing I’m addicted to. I can’t get enough. I drink more than 10 glasses a day."
1965 (earliest)
Although there may be other causes for a big "healthy-looking baby staying sickly," we can find the answer to your baby's problem in your letter. Your baby is a "milkaholic."