Can anyone help? Our 8 month old pup has started to cock his leg indoors, he's not fussy where, furniture, curtains, doors in the hallway.  There is always someone at home with him, not always in the same room, he has his quiet time in the kitchen, when he has a nap, but has plenty of time outdoors as well as inside.

We don't always manage to catch him in the act, however being a one dog household we know that its him.  Obviously,when he has cocked his leg and we miss it, we cannot tell him off.  But can anyone explain why he has started doing this?

We have had numerous dogs over the years, living long and happy lives, its been a time since we've had a pup, we don't recall this happening in the past.

It can be quite nornal in a male pup where other dogs have been before him - he's putting down his scent or making his mark. You really need to catch him in the act in order to curtail it.

I assume you want your pup to stop?  Then make sure you're cleaning up in such a way that you eliminate any trace of scent he may have left behind - this means washing down with a solution of biological washing powder, then wipe down with white or surgical spirit.  If you catch him at it - clap your hands or run away to distract him (then clean down as described)