Thank you for that information. since it has been going on for two years then it is likely the dog is marking and not peeing. If you were to say that this just started then I would want to look at a possible health problem but it does not sound like this would be the issue. However it never hurts to drop off a urine sample for testing of stones or a prostate problem.
Marking is not the same as peeing, that is why your corrections have not done anything and that is why he does not use the doggy door to go out. His intention is to leave his mark behind in the home for whatever reason. It could be some competition you are not noticing between the dogs that started two years ago.
Marking has to be dealt with differently than peeing because the act is not the same.
Below is my article on how to handle marking.
Copyright Sally G
Unfortunately marking does not have a ‘reliable’ training behavior modification such as we train for eliminating outside. Marking is an environmental and hormonal influence / instinct of hierarchy so it is rarely trained out of a dog. Dogs convey their status through pheromones that are in the urine. It also has to do with a dog’s confidence. A dog that is confident usually marks every tree and fence post, a dog that is not confident usually only marks close to home areas such as the front and back door or inside the home, thus he is only claiming his immediate area and not a whole outside area.
There are a few things you can try that may or may not work but for some they have worked. Clean all areas the dog has gone in with a cleanser made just for dog urine to eliminate the previous odor. Then sprinkle some of the dog’s kibble or treats in the area so he begins to see these spots as an eating place. Dogs do not usually like to eliminate where they eat or sleep. Eventually you can try putting small bowls of water in those spots so it lasts longer than the kibble but we want to put food their first so it is viewed as a specific eating place.
Many owners play a role in marking through lack of training as well. They put upon the dog the task of being a protector of the home rather than taking the lead role through daily training. This confuses the dog as to where its place is in the home.
You will find that dogs that are crated or gated in a small space will not mark that space because the feel confident they own it, there is no confusion.
As part of an environmental modification
*Try to block outside influences that the dog may be seeing out of a window or door.
*If you have company make sure the dog does not have access to their belongings
*If there are conflicts in the home with another animal you will need to resolve that conflict.
*Ask the dog to obey a command before you give it anything as this can establish you as the higher up in the home.
*If it is due to anxiety then talk with your vet about medication or you can try over the counter melatonin. Melatonin found in drug stores by vitamins
* If he is marking in multiple spots inside: Get a bandana and put some of his urine on it. When the urine has dried put it around his neck whenever he is inside. Now his “smell” will be everywhere he goes, and will reduce or eliminate his urge to urine mark to place his smell inside your home.
Belly bands for males can also help. https://www.amazon.com/Brookes-Best-Belly-Bands-Black/dp/B01GZ6R3UC/ref=sr_1_1?s=pet-supplies&ie=UTF8&qid=1470001741&sr=1-1-spons&keywords=belly+bands+for+male+dogs&psc=1
Aside from that the best an owner can do is never to allow the dog to have run of the home either the owner’s home or another’s home. If you want him in a room with you and out of the gated area it is best to tether him to a spot near his bed in that room. Some owners will tether the dog to themselves so the dog has to move with them from room to room and it makes it easier to keep an eye on the dog.
Shouting ‘no’ or any type of punishment or reward system at the time does not really work because it is not a behavior but a long engrained instinct.
Daily positive obedience training may also help as the confidence is boosted and you are seen in a different light. I would try clicker training as this sets a dog up for success which builds the confidence.