Hi all, I'm new here, and I am looking for some advice.
I have a now 9 month old Standard smooth haired Dachshund x, called Colin (I also have a "Jackuahua" called Luci, but she is an angel!).
My husband and I bought him from a breeder of chihuahuas and shi tzus (the Daxi was a family pet) aged 4 months, so we have now had him for 5 months.
He'd previously been paper-trained, but we wanted to housetrain him, so we started almost straight away.
It took ages, and he was SO stubborn. However, a few months ago, we'd cracked it and Colin was going through the night, and was fine through the day too (they're only left on their own for a max of 4 hours, if mine and my hubby's shifts overlap).
However, a few weeks ago, he began to wet and soil in the house again, so I put him back in his crate overnight and when we weren't able to supervise. I have no idea why!
At first I thought it was behavioural, and I assessed everything, thought it could be Colin preferance to Luci's bed, bought him one the same, left him out of his cage overnight, and came down in the morning to a wee

He is neutered, and I know from the quantity of wee that he is not marking.
I'm starting to think Colin has actually just decided he doesn't want to wait to go out and that if he needs to do a wee or poo, he's going to do it, regardless of where that is.
It's frustrating.
Also, Colin doesn't wet and soil my floor, which I could cope with. Instead, he chooses my sofas (which I cover with shower curtains as a precaution, as he's done this before).
As he NEVER does this in front of me, I can't ever tell him off for it, so he goes on thinking this is acceptable.
He knows 150% where his toilet is.
I just don't know what to do.
I've read lots of books, and as I said, was successful before, but don't know what to do now.
Temporarily, he's back in the crate, but I really hate putting him in there (he doesn't mind though) because the idea of having 2 dogs was for them to be company for each other, but when Luci has the whole room, and he's shoved in a cage, they're no company for each other at all.
Please help.
Any advice will be greatly appreciated.