961 Hi Roger,
First impression is that it sounds like a marking incident, especially since he sleeps near the spot and Blade is at the age where you may see that.
Here are a few things that may help us understand why:
1. Is he intact? Neutered dogs will still mark, but intact tend to do it more.
2. Have you had any visitors recently – 4 legged or people? Sometimes you will see the marking behavior after (or during) a guest has been in the home as a way for the dog to feel more secure about what is his is still his. For instance, I once had a client who’s dog would only mark in a bedroom after the son came home from college and slept in the empty room where the dog usually stayed.
3. How have the pack structure exercises been going? Sometimes if we ease it up too much with the pack structure stuff – especially the affection rules you may see the dog have a tendency to start marking the home in general.
Let me know when you can, and we can make a plan.