doggie door

I have a Pet Safe doggie door that is like rubber with a magnetic strip on the bottom and the whole thing fits in the sliding glass door area. Its a great doggie door but my issue is how to get the 1.5 year old puppy to stop eating the plastic. I tried bitter lime spray but I think she thought...

Do any of you have doggie doors for your golden retrievers? I'm just worried that I would need to get a pretty big door, and that people would be able to break in that way. The thing with Rose is that she's getting a little old and it probably would be uncomfortable for her to bend down too much...