I have a fixed one and a half year old male basset hound blue heeler cross. I've had him since he was 9 weeks old, he house trained quickly but now all of a sudden after all this time he has started to poop on my floor, its always the same spot so I put up a baby gate so he couldn't get to it. That worked for about a month but now he has chosen a new spot. I don't work so am always home to let him out when needed, I've taken him to the vet and they say he's perfectly healthy. I've used special cleaners and vinigar on the spot where he goes but it doesn't seem to deter him and he knows its wrong, alls I have to do is point at the mess and tell him bad and he hangs his head and lays down, but until I find it he shows no sign that he was bad. Can anyone tell me why he does this, please help!

Are the stools firm and formed or lose and watery? Have you made any changes in diet? Are there any new members moving in or out of the home? Even the simplist of changes can effect what your dog hears,sees and smells which can cause changes to his bowel movement habits.

So is your dog pooping in the house even when you are home? What is daily routine like? Are you making sure he is going outside right after he eats or drinks or plays? Even the smallest amount of kibble can put pressure on his bowel creating the urge to go. Is he getting lots of play time and exercise outside like walks or runs? The more active your dog gets outside, the more chances he gets to relieve himself in appropriate places. When he does do his business outdoors praise like mad. The only problem with punishing your dog after the fact is that your dog will realize that it's the poop that is making you mad, not the action of doing it. That's when we start to see dogs hiding their messes. A lot of time unless you catch him red pawed doing the deed, any sort of punishment can be quite counter productive. AS frustrating as it is to just ignore him and clean it up, that really is the best method. Believe me when my dogs have accidents, there is a lot of grumbling going on while I am doing the cleaning.

There really is only two reasons for a dog to start messing in the house one is medical (which can also be diet related) and the other is behavioral. Since you have the medical ruled out, it's just a matter of positively reinforcing the good behavior you expect. This means going back to basics and house breaking as you would with a new puppy.