Your Question: My husband & I have a 5-month-old dachshund/spaniel female puppy who has started to pee & poop on our bed whenever we go out for errands or are at work. Although she doesn't do it every single time we're out of the house, she has been doing it almost every other time (we make sure to leave clean puppy pads out for her when we're not home too). When we're at home, she's well-behaved and knows that she isn't allowed on the bed unless we invite her, and she pees & poops when we take her out. We're absolutely at our wit's end, and aren't sure what the cause of this behavior might be. Is it separation anxiety or is it an assertion of dominance? How do we correct this behavior? Thank you.
Thanks for your inquiry. I would begin by confining the dog when you are gone. An ex-pen, some baby gates in a hallway or a crate would do it. It may be connected to separation anxiety - hard to tell. Check out the section regarding separation anxiety on this site and see if you find anything useful there.
Also, a five month old pup, no matter how good she's been doing on housebreaking, IS NOT housebroken. You can't consider your pup reliably housebroken until she's six to eight months of age and hasn't had an accident in two months. Prior to that it's on you to confine, supervise, regulate the pup until that target has been reached. You can check the housebreaking section on this site as well. Lots of helpful info there.