The slopes and peaks of desert mountains often are made of very sharp lava flakes. This surface will easily cut a dog's pads. Boots for the dog may help in extreme cases, but the dog must become accustomed to wearing the boots before it can be expected to work in them. The handler must remember that one of the ways dogs lose excess heat is through their feet, and boots may compromise this cooling mechanism. Spiny plants are the rule, not the exception, in the desert.
Cholla is the worst plant to encounter.
Clumps of cholla easily break off from the plant and stick in the dog. When the dog tries to bite the clump in order to remove it, the spines of the cholla will stick in the dog's mouth. The spines of cholla are barbed similar to a fish hook and are not easily removed. Experienced dogs learn to wait for the handler to remove the cholla. A coated dog actually does better around cholla because the barbs are more likely to be caught in the hair rather than the skin.