I have 2 boxers (white and bridle) we bought a dog door for the White one when he was 2 (Dutch) Then Loki came along 1 year later. He got on real quick to go outside to potty using the dog door. I was worried the first time we left him that he would go on the floor or carpet. But he held his water and - till we got home. I can't remember how old he was I'm thinking only about3 months.It worked or us and I never had housebroken a puppy so quickly or easily in my life. Of course have another dog probably helped too.
Dog doors are great except that they do not teach a dog to hold their bowel and bladder. They essentially give 24 hour access to the outdoors for whenever the call of nature arises.
To REALLY housetrain a pet it needs to learn to hold bowel and bladder until it is given access to the area approprite for elimination. The only way to do this is by confining the puppy and getting it on a strict schedule of trips outside. Please don't wait for the dog to tell you when it has to go. Many people make this mistake and in essence set themselves up for failure. What happens when the dog has to go potty and no one is home? Is the dog wrong to give the I need to go signal and then has an accident because no one if home to see it? Avoid the waiting for a signal and get the dog in the habit of waiting to go until it is given access to the out of doors. By using a schedule for meals and potty trips, your pup will catch on very fast to the program and I'm sure will do well at learning to "hold it". Once that is accomplished, by all means go back to using the door safe in the knowledge that the dog can hold it for longer if need be.
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