My wife and I have been RVing with two dogs since 1998. The constant concern is where to securely tie them up without being in the sun or bothering the neighbors. One of them is an 85-pound Labrador retriever that can move picnic tables, when he spots someone who might pet him!
We solved this by mounting eyebolts under the coach. The eyebolts were affixed at solid points, and sealed.
You can tether the dog to the eyebolts using whatever length leash you find offers decent roaming room without inadvertently allowing the animal to hurt himself; even the shortest tether still lets him relax under the RV, in the shade.
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