Guard dogs have been proven a useful tool for reducing sheep losses to predators, and are very effective when full-time members of a large flock.
Llamas and donkeys are also often kept in sheep pens to scare off predators.
Donkeys have been used for centuries to protect sheep and other herding animals, and are extremely intelligent, with acute hearing and sight.
Guard llamas have become popular guard animals in recent years, and are instinctively alert, social, and aware of their surroundings, and can be trained to herd the animals they are guarding into a tight group or even lead them away from danger.
Llamas have also been known to kill predators such as coyotes.
Llamas and mules may look soft and cuddly to you, but they have bad tempers and tend to kick hard at marauding wild dogs and wolves.