4 Month Set Backs PLEASE ADVISE

So, Milos 4 months now. Training going well, got Milo into puppy school (top of the class in my opinion), heel and walking off lead perfect and starting to see the bond with Milo and my wee boy Aidan (see Staffy vs Baby video). Problem i have is that Milo has started peeing in his crate, on his everyday bed and any blankets put down for him. Its only little amounts and very frequent and he doesn't mind lying on it. Wondering if he's scent marking because it doesn't matter if he's only just walked in the door from a walk or if he's been sitting chewing his bone for half an hour. Do hormones affect male dogs aswell and at this age?

He should be teething at that age and the behaviour could be attributed to pain. Make sure he has plenty of frozen treats like sliced carrots, sweet potatos or a frozen kong to help with the pain.

He is also scent marking so you need to remove the smell completly to discourage the behaviour.

It's also possible he either needs a little more exercise or mental stimulation such as an extra training session or a game of find the hidden treat to tire him out.