Gosh, this is taking me back. Sophie, my last cocker, used to love Lactol, in fact my mother in law, who only lived just up the road, always kept a tin in and gave her a bowlful each time she visited, which was at least once a week. I also kept some in and gave it to her. I used to think of it as a vitamin drink for her. It certainly didn't do her any harm, she lived very healthily until she was 14.
Ellie didn't like it as a puppy, might try her again on it now she is older.