Other guard animals like dogs and donkeys do not meet these requirements quite as well. Llamas adjust to the sheep within hours to weeks, graze the same pasture, eat the same grain, get the same vaccines, can be used for 10 to 15 years and are effective guard animals. Llamas require more of an initial investment than dogs, but actually end up costing less per year of use than dogs. It takes less time to find out if the llama will actually work as a guard animal and there is a higher rate of success than with dogs. There are a few farms which test the guarding ability of llamas and sell them as guaranteed guard animals.
Llamas are useful guard animals for almost twice as long as most dogs.
Dogs require more acclimation time, different food and vaccines than the sheep, and are only useful for 3 to 4 years. A gelding laying with a sheep from the herd he protects. A single llama with a flock of sheep is the most effective situation. There has been a documented decrease in sheep losses when a llama guard is present. Single llamas can be used for flocks as large as 2,000 sheep or as small as just a few.