We ordered the biggest, reinforced dog door from you last fall for our two Great Danes. It works wonderfully, even keeping out the cold winters we have here. But, I had to tell you that the first pets to use it were our 10 lb. cats! They have NO trouble getting in and out of it, often with live chipmunks or mice in their mouths! If anyone is worried about the doors being too tough to use, tell them NOT TO WORRY! LOL!
Thanks for a great product!