house-training

Question
Hi, I have a 5 month old male Golden Retriever.  He has been completely house trained since he was just a wee pup.  However, I can't seem to train him to notify me when he needs to go out.  I just let him out every time he goes towards the back door.
The other night when we got home from the dog park, he downed a couple bowls of water which resulted in him not being able to hold it all night...which then resulted in him peeing on the kitchen floor.  I am a light sleeper and would have woken if he barked, or nudged me, or anything.  It's also a problem if we go to someone else's house as he's not always sure where the door is.
Any suggestions?  I get him to "speak" before I let him out, but after several weeks he's still not making the connection.
His accidents are very rare, but I want to give him a better way to communicate!
Thanks for your help.

Answer
By the time most dogs are about 3 months old, they have figured out that if
they go to the door and stand, you will let them out. The praise, you should have been giving him outside, slowly shifts to going to the door. Some people hang a bell there for the dog to paw. If your dog doesn't figure this out, try praising it and putting it out if it even gets near the door.

When you visiting somewhere, you sort of have to take over managing the toilet times.  We had a real challenge last spring when we took an 8 week old Golden to a convention and spent most of the weekend in a nice convention center.  You just need to anticipate when he needs to go out and take him out.  Better a few too many times.