dog starting to pee in the house

Question
QUESTION: my dog is 10 months old,iv had him from 7wks old,he is not a house dog,he is out in our back garden,we leave our back door open part of the day,he will come up to the door but he knows not to come in the house he has known this from day1 and we have never had a problem ontil a few days ago, he decided to come in and he pee'd on the floor in frount of our wash room and a few days later he did it again in the same place and a few days after that he done it on the kitchen floor,and he does it when no1 is around.our cat keeps sneeking in the house and we keep putting her out and the dog seems to have picked up on the cat is not aloud in the house and her room of choice is the wash room,we put a chair at da door to stop him coming in which is fine,but if you have any suggestions or advice on the subject,that would be great.thanks

ANSWER: Why ANYONE would deliberately -- DELIBERATELY -- acquire TWO ANIMALS and then FORCE them to remain isolated outdoors seven days a week is beyond me.  Dogs SUFFER in isolation, they REQUIRE the company of their human family.  The dog is desperately attempting to BELONG, he does not want to be in SOLITARY CONFINEMENT in your backyard.  You should be ASHAMED of yourself.  You are barking up the WRONG BEHAVIORIST. Address your question to someone who doesn't feel the need to TELL YOU THE TRUTH.  I am an advocate for the dog, not for abusive, neglectful owners. Next time, GET A STUFFED ANIMAL.

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QUESTION: well your "help" is greatly appreciated I can see why your a professional in your field!!! but I will ask my question again in SIMPLY TERMS!!! Why after 10 months does my dog(which are animals that live out side(not "TOY DOGS")Outside being their natural habitat)now decided to come in to the house to pee it has never happened before.
I have over 1 acre of back yard. not a SOLITARY CONFINEMENT!!! how dare you say that you are a professional in your field, when you cant answer a question without verbally attacking my ability to look after my animals, quite clearly this is what you use when you don't know how to answer a question. I will invite you to come see how I look after my animals and you can then try and say that I am an abusive and neglectful owner.
Get over yourself and be professional.
Your abusive nature has be reported.

Answer
People who subject their animals to ABUSE AND NEGLECT get what THEY DESERVE when they ask me a question.  Your dog is suffering from psychological and emotional ABUSE.  You do NOT "look after" your animals; you subject them to isolation and emotional abandonment.  YOU ARE abusive AND neglectful.  Furthermore, to think that you can rehabilitate the damage you have caused by asking a question on the INTERNET suggests other things about you I would rather not mention.  Find yourself a bleeding heart who will lavish you with free advice and  attempt to compensate you for the guilt you must be feeling.  I am not that person.