Friends of ours have a dog kennel that also doubles as an end table in their living room. Theirs is finished and has a door. Their slats are 2x2.

It inspired me to make some for our dogs. we have two. I still need to trim them and finish them.

These are great. A lot of people don't even notice that they're dog kennels until the dogs go in, or out, or make some noise. So far we haven't needed doors but it's still an option.