housetraining a male Maltese

Question
We bought a 1-year-old unneutered male Maletese 2 months ago.  We were told he was house trained and would scratch at the door when he needed to go outside.  He has never done this even once.  We take him outside every 2 to 3 hours and he goes.  That has worked okay except that we have to watch the time closely. Two exceptions were the first day here--he had 5 "accidents" on the rug and furniture, and another day the vacuumed scared him and he made piles all over the living room.  He has had some stomach upsets when my husband has tried giving him pork chop bones and peanut butter as treats and he has had diarrhea and has messed in his crate and on our rugs.  Last night he drank 3 dishes of water and even though he was taken out afterwards, in an hour he wet all over 3 rooms.  I am tired of cleaning up after him!  Is there any way to train this dog to let us know when he needs to go outside?  Or are we not observant enough to realize the signs that he is giving us?  Neither of us have ever had an indoor dog before so we are clueless.  Thanks for any help you can offer.  He's a smart little guy and always happy and we just love him.

Answer
Ok firstly do not feed any pork products pork is toxic to dogs along with chocolate, onions and raisins.
I just think he is taking some time getting used to his ned environment. the breeder probably exaggerated his skills lol.
i suggest getting him into a routine of going out at certain times of the day  regular wait with him then fetch him in and repeat eventually he wil realise where he has to go and in order to get there he will have to scratch at door. also clean carpets where he has already been as the smell will encourage him to go back
good luck