Hi!
I used to travel with a yorkie and two shihtzus. The yorkie and older shihtzu have crossed the Rainbow Bridge so I am left with one shihtzu now.
Barkie little dog, fearless/stupid. I have certain rules with her when boondocking...well...all the time.
1) She is ALWAYS leashed when outside the van or if the van door is open, she is leashed to the inside of the van. Once she jumped out to greet a friend, so now she's attached to the van if the door is open. NO exceptions! ALWAYS! I can't control what other animals do, but on a leash, I can control her. And she wears a harness. A collar can slip off.
2) I am always close by, especially if the doors are open.
3) When she is outdoors with me, I carry pepper spray, bear spray, or a big stick.
4) I walk her only in daylight. If it's dark, she stays inside the van. Period.
Wild animals have never been a problem. Other campers' dogs off leash have been. I have had to pick her up to keep her safe from them. She is my best friend and closest companion. My travels are often planned around her comfort (we go where the weather will be okay for her). I wouldn't have it any other way.
Best wishes and happy trails with your little friend!