For removing cholla (choy'-ya) cactus tines from my dog, I've found that a small set of needlenose plier work well. You just can't pull many of them out by hand. Cholla is the nastiest cactus I've encountered. The tines are about 1 1/2"-2" long and are microscopically barbed. I've decided I won't hunt in the stuff with or without my dog. I've ridden horses thru forests of the stuff and pulled out literally thousands of the tines from dozens of horses. My lab took a half hour to remove the tines from one encounter. No more.
