Dog just peed on his blanket

[ChickensHaveNoEyebrows]

He is 20 months old, neutered and house trained. We just got in from a walk, and he scratched around with his blanket and circled on it like he was going to settle to sleep....except he whizzed on it instead. My yell of 'NOOOOOOOOOOO!' cut him off midstream. The blanket was on my rug, so I've scrubbed it with a biological washing powder solution and stuck the blanket in the machine. But why would he suddenly do this?

I have no idea, Chickens , but as mummy to a 20 month old lab/springer cross I am interested, so I'm bumping this!

marking his territory?

Devil Dog does this. The first thing he does when he gets a new bed or blanket is to pee on it, he never pees on shared beds or the other dogs beds, just ones that are put where his beds belong. I'd always just assumed he was marking it as his. He pees once and then he's happy.

Huh. He's had this blanket since he was tiny, but I had just washed it. I usually use non-bio washing liquid, but have just switched to bio. Maybe it didn't smell right

It probably didnt smell right my dog (lurcher springer cross) does this when I wash her stuff. I find making sure it dries outside helps.