Hello everyone, I have an 18 month old rescue dog and her six month old male puppy. A week after we first had her she got all exited and did a wee and a poo upstairs, our fault really, we hadn't made sure she'd 'been' before giving her the run of the house - anyway, she had one more accident - a wee - but she's been as good as gold since.  They both sleep overnight in their baskets in the kitchen, and when I'm at work (never leave them longer than 4 hours) they stay in the kitchen, so it's really their 'den'. The puppy has been clean for ages and wees and poos to commands, his Mum is more reluctant to go when asked but has improved loads.  I used to have to get her lead on every night at 10.30 p.m. and take her for a wee because she wouldn't do one in the garden, but she does now every night.  Yesterday I replaced the kitchen door mat, they lie on it a lot and it had started to smell 'doggy', this morning there was a wee on the new one!  I don't know which one did it as they both 'performed' as normal after that.  Do you think one of them 'marked' it? and if so, am I always going to get a problem when I put new things in there?  Any suggestions please?

Marking is common in adolescent dogs - and your pup is just reaching that stage.  The best way to stop it is to clean up appropriatly (biological washing powder solution followed by a spray when dry of surgical or white spirit to stop the smell lingering. DO NOT use cleaners which turn white in water, they contain ammonica which is chemically very similar to urine - this encourages the dog to return to mark the same place again)

HTH