We have a cat door and both my yorkies - 7.5 and 5.5 lbs go thru it and I have a 12lbs pom mix that goes thru it also very easily. I have one yorkie that will go outside no matter the weather to go potty and the pom mix will too. But I have another yorkie that does not like to go if there is inclement weather, so we do put a potty pad down. They love the door, because they can run out the door and bark at things that come along the way.
