This would work well for cats, but is not even close to acceptable for a dog.  We have a Golden Retriever puppy who would just push this thing out of the way to get through.  The construction is not even rigid enough to keep the door closed.  I've even tried to add extra braces to keep it in a position where the door will keep closed, which helps, but if the dog tries hard enough he can push the door open.  

Pros: Looks good when brand new
Cons: Too flimsy, way too expensive considering the quality.