Truck Camper Pass-Thru Cab Windows and Dogs

I would drop that choice from consideration. Not counting pets, the opening is essential to keep the camper at a reasonable temperature when driving on very hot or cold days.

Never had dogs going through the window. But my wife use to, to use the bathroom or bring a snacks up to the front. That was a long time ago and yes I know it was not safe :)

In the old days we used to remove the truck rear window and have an upholstery shop fabricate a boot between the camper and the truck. It was great. My dogs would lay in the camper and look out through the window. One time I had to stop quick and both of them were asleep, they slid into the back seat. They both had the look "What happened, Why'd you do That ?" They weren't hurt just surprised.

My dog would never fit through a pass through window in the first place. She's a BIG girl.

I used that mostly for cooling down the camper by recycling truck cold air, but having dogs jumping between for driving was icing on the cake.
The small electric window on new Ford works just fine with older camper, although getting good seal is problematic.
I had inner tube, but that one deteriorated very fast in summer.
Bought special seal from Walmart (special order) but that one is flat, when my gap has 2" taper.
For next season I am planning to add 2" of Styrofoam above the truck window, mounting it with dual-side tape and hopefully that will work.

Our dog goes back and forth from the camper to the back seat of the crew cab through the cab window on the camper. We also use that window to cool the camper while on the road with the truck AC and warm it up in the winter with the truck heater. We do have a boot that fits between the cab and the camber window.