A guard dog or watchdog is a dog used to watch for and guard people or property against unwanted human or animal intruders. A dog trained to attack intruders is known as an attack dog.
History
Dogs have been used as guardians since ancient times. The ancient Romans placed ''Cave canem'' mosaics at the entrance of homes to warn visitors and intruders of the presence of dangerous dogs at the property.
One of the first dog types used as guardians were
Mastiff
A mastiff is a large and powerful Dog type, type of dog. Mastiffs are among the largest dogs, and typically have a short Coat (dog), coat, a long low-set tail and large feet; the skull is large and bulky, the muzzle broad and short (brachycephal ...
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landrace
A landrace is a Domestication, domesticated, locally adapted, often traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural Environment (biophysical), environment of agric ...
wolves
The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...
leopard
The leopard (''Panthera pardus'') is one of the five extant cat species in the genus ''Panthera''. It has a pale yellowish to dark golden fur with dark spots grouped in rosettes. Its body is slender and muscular reaching a length of with a ...
s. In
Greek mythology
Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories conc ...
, Orthrus is an example of a livestock guardian dog known for guarding Geryon's red cattle. In more urban areas, some ancient guard dogs, such as the extinct bandogges, were chained during the day and released at night to protect properties, camps and villages.
Barking
Guard dogs bark loudly to alert their owners of an intruder's presence and to scare away the intruder.
Livestock guardian dogs are often large enough——and strong enough to attack and drive away livestock
predator
Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
s. Guard dogs bark to alert their master and to warn of approaching animal or human threats prior to their interception of the trespasser.
Specifically, livestock guardian dogs such as the Kangal use loud alarm barks as a first line of defense against presumed threats; if these do not deter a perceived foe, other displays, such as bluffing and charging, are employed. For livestock guardians, proactive forms of defense such as biting are only used if all other forms of deterrence fail.
If the risk is from human intruders, a suitable dog can be trained to be aggressive towards unrecognized humans and then tethered or enclosed in an area that the owner wishes to protect when he is not around (such as at night).
Breeds
Many currently prominent guard dogs started as general purpose farm dogs, but gradually developed into guard breeds. However, dog breeds such as the
Dobermann
The Dobermann is a German list of dog breeds, breed of medium-large working dog of pinscher type. It was originally bred in Thuringia in about 1890 by Karl Friedrich Louis Dobermann, Louis Dobermann, a tax collector.Dogue Brasileiro were specifically bred to guard. Guard dog breeds tend to be territorial, averse to strangers, dominant, and protective and loyal.
Legality
The laws regarding ownership and usage of guard dogs vary from country to country. In England, the main legislation relating to the use of guard dogs on commercial premises are contained within the 1975 Guard Dogs Act. The act specifies the requirements of kennels and the need to display guard dog warning signs at the entrance to sites.