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. Cholla is found more in the low Colorado Desert than in the high Mojave Desert. A simple rule of thumb is to not work a dog in areas of heavy cholla. In areas where the cholla is not so prevalent, it may be feasible to work an area search dog, however, working a trailing dog on tether may be difficult because the line may pull the cactus clumps into the dog. Yuccas are often encountered as many species are found throughout the desert.