How do I tell my friend he is a slob?

He is a great guy. Very personable and articulate but he smells of body odor, his place is a filthy mess. He never throws things away, his halways are narrow corridors with books and junk pilled up along the sides. You cant see his bed room floor for all the newspapers, books , chip and food containers. He has several pets and they are living in squaler. The kitchen is dusgusting and food is everywhere rotting. The whole house is just totally disgusting. I dont want to get him in trouble but is there an agency I could call about him and what would the ramafacations be?