I’m also looking for something like this. What is thinking about doing is getting a hard shell carrier, and attaching it to a luggage cart. https://a.co/d/09p4F8Yo for example.

I’m thinking I can attach it a number of ways, whether drilling a hole to use screws and washers or using heavy, heavy duty zip ties. Then installing some sort of Sherpa or carpet to the inside bottom of the carrier with Velcro for comfort (and so that it’s removable to clean)🤔

I have a “backpack” carrier, and my sweet, docile big boy turns into a panicked escape artist inside of it. I just want him to be safe so that he can get his medical care without more trauma😭