My Little Mac has been lifting his leg since we got him at 9 weeks of age. He started marking around 4 months of age. I had him neutered at 6 months and he has now stopped about 95% of his marking maybe even all of it. He used to mark his older "brothers" beds when he got the chance as well!
He still lifts his leg now but it's for a real good long pee
not just 2 seconds of marking.
It's only been 5 weeks since Little Mac was neutered.