I'm building the kids a Pet Clinic in their playroom. I really wanted to incorporate a kennel area but didn't want to use actual dog kennels. They cost so much and weren't safe for the kids. I'm so happy with the way this came out. It's an Ikea expedit shelf with gates added to the shelf openings. Here's how I did it.
Here I screwed the double roller catch onto the inside of the the expedite shelf. I made sure that it was aligned with one of the gate rails prior to securing it.
I flattened the spear strike so that it would cover both gates and bent it back so I could fasten it to the inside walls of the expedit.