marking in the house

Question
We have a five year old Bichon.  He has been crate trained and after five great years he has began marking his terriotory in the house.  He does it very sneakily if that is a word, so we do not find it for days until we stumble across a yellow stain on a rug.  We love the dog and he gets plenty of attention. The kids are devestated about the notion of getting rid of him.  He has been tested for bladder issues and is perfectly healthy. Is there anything you could suggest to break this behavior?

Answer
Why on earth would you need to get rid of him because he is showing the world that HE loves YOU.
If you are willing we will take you through step by step training log into www.eurobichons.com

We have a post on here also about why my male dogs scents , please read it and you will cry due to understanding why they actually do it xxxx