Hot answers tagged adnd
The 3.5e magic item Horseshoes of the Zephyr will allow your nightmare to run slightly (and inch or two, if I remember right) above the ground. This is usually simply used to avoid leaving tracks, but seems to be a very efficient way to solve your problem by never touching the dirt or road. It requires Levitate to create, and so should be available at early ...
Only top voted, non community-wiki answers of a minimum length are eligible