What does Clinton Anderson say about horses that are hard to deworm and how do you train them to accept it?

Clinton Anderson addresses worming resistance specifically because it is one of the most practically important routine health care tasks that many horse owners dread, and he frames it as a straightforward desensitization and acceptance exercise that most horses can be conditioned to accept easily with proper preparation. Anderson's diagnosis of why horses resist deworming is usually one of three things: the horse has learned that pulling back or throwing its head away removes the syringe — meaning the handler accidentally reinforced the resistance — the horse was wormed forcefully at some point and now has a fear response to the syringe near its mouth, or the horse has never been systematically taught to accept oral medication and simply does not know what is being asked. His preparation process uses an empty or dummy syringe filled with something the horse finds palatable — applesauce is his documented recommendation — and practices the worming motion repeatedly before any actual dewormer is administered. The syringe is introduced at the corner of the mouth, the plunger is depressed giving the horse the applesauce, and the handler does not release the horse's head during or immediately after — maintaining contact until the horse is relaxed and accepting. Over several sessions of this positive association, the horse learns that a syringe at its mouth means something pleasant and stops resisting. The key training point Anderson makes is that the applesauce sessions must have the same body position and approach as the actual worming — same hand on the nose, same approach angle, same timing. If the preparation mimics the procedure exactly, the horse cannot distinguish the preparation from the real thing and accepts both equally. He notes that horses prepared this way can typically be wormed by anyone without assistance, which is a significant practical benefit at veterinary visits and in commercial boarding situations.