I would try this. Do you have a basement with a concrete floor? If you can, set up a pen with an attached crate. I bought chain link fence gates and clamped them together and used a chain with a double end snap where I could go in and out. You can attach each section together with zip ties. Then use zip ties to include the crate. You can also use an X-pen. Get a rabbit pan (they are available at Tractor supply) and get some pine (not cedar) shavings OR shredded paper and put that in the rabbit pan and put that in the exercise area of the pen. MOST dogs when left for an extended period of time will choose to pee and poop in the rabbit pan on the shavings. The point of this is that the dog can relieve himself in an appropriate place while you are at work and the dog MAY figure out that the crate is for eating and sleeping and is not an outhouse.
When you are home, the dog is either confined in this pen or is in sight. Put leash on the dog when in the house. If you go in the bathroom, the dog comes with you. Keep up the rewards outside for pee/poop there and simply give him NO opportunity to use the house as a bathroom. It will take a lot of vigilance. It is a lot easier to clean up that rabbit pan than pee or poop in a crate. I assume you are using a plastic den-like crate (that can be helpful).
It is likely that this dog was kept in a crate and allowed to be dirty when he was younger. THAT is the same issue that happens with pet store and puppy mill type puppies. They accept being dirty. Your job is to reverse that and it is a long process and a lot of work.
It is also possible that somewhere along the way the dog was punished for going in the house so he will go where and when he wants but only when you cannot see him.
The thing with training any dog to do anything is to repeat the correct behavior. This means that you need to help him to have a pee and poop area that is NOT in the crate and to see if he can figure out being clean is better (when you cannot be there). The rest of the time you have to be 100% on top of the situation so that there are NO accidents. It is a lot of work and I wish you every success.
When you are home, the dog is either confined in this pen or is in sight. Put leash on the dog when in the house. If you go in the bathroom, the dog comes with you. Keep up the rewards outside for pee/poop there and simply give him NO opportunity to use the house as a bathroom. It will take a lot of vigilance. It is a lot easier to clean up that rabbit pan than pee or poop in a crate. I assume you are using a plastic den-like crate (that can be helpful).
It is likely that this dog was kept in a crate and allowed to be dirty when he was younger. THAT is the same issue that happens with pet store and puppy mill type puppies. They accept being dirty. Your job is to reverse that and it is a long process and a lot of work.
It is also possible that somewhere along the way the dog was punished for going in the house so he will go where and when he wants but only when you cannot see him.
The thing with training any dog to do anything is to repeat the correct behavior. This means that you need to help him to have a pee and poop area that is NOT in the crate and to see if he can figure out being clean is better (when you cannot be there). The rest of the time you have to be 100% on top of the situation so that there are NO accidents. It is a lot of work and I wish you every success.
