Do you prefer the drop lines with cable drops, or chain drops when camping?

One problem I have seen with the drop line is that I attach the drop line to two trees using some ropes. The problem is that sometimes the dogs like to "chew" or pull on the rope attaching the drop line to the tree.

Are there any drop lines that you have found where the dogs can't reach the rope and chew on it?

Maybe there needs to be a longer length of cable on each end of the line?