Join Now. Few things can disrupt the harmonious bond you have with your dog like urinary issues. When your house-trained adult dog uses your house as his personal toilet, you may think he's doing it out of spite and that he needs to be scolded for his wrongdoing. But the truth is that inappropriate urination in dogs is often beyond their control and usually has an underlying cause that has nothing to do with bad behavior. A number of reasons could account for why your dog is peeing inside the house. It could be something as simple as he's drinking too much water and needs to go more often than he's able to go outside.