We moved to the suburbs in Jan and now are blessed with a fenced backyard so Bentley can be let out to potty alone. He is almost 2.5 years old and I'm wondering if a doggy door to the backyard would be too hard for him to adjust to at this age. We'd hate to install the thing, only to have it sit there unused. It would be convenient for us, so that our ears wouldn't have to be in tune to the sounds of scratching to let him out.