The main function of a livestock guarding dog is to alert humans when carnivores approach the livestock herd, but the typically large bodied livestock guarding breeds may also be able to deter carnivores from attacking the livestock. The dogs live with the livestock herds and regard the herd as their pack. Descriptive studies have looked at various aspects of guard dog training, different dog breeds, and owner satisfaction.
Five studies have evaluated the effectiveness of livestock guarding dogs congruent to the standards of EviWild evidence. Four of the studies included livestock guarding dogs that were of traditional guarding dog breeds. The dogs reduced the risk of coyote predation on sheep and lambs both in fenced and unfenced pastures as well as on cattle, and the dogs reduced wolf and brown bear predation on sheep. The effect of the livestock guarding dog is likely affected by the size and behaviour of the sheep herd, if the dog is unable to attend all sheep predation may still occur in unattended parts of the herd. One study evaluated the effect of the presence of domestic dogs, that were not of the typical livestock guarding breeds, in African bomas. Increasing numbers of these domestic dogs reduced the total risk of carnivore attacks on livestock in the boma.
