Attack dog

An attack dog is any dog bred, trained or used for the purpose of attacking a target either on command or on sight. Attack dogs generally receive extensive military training in tracking and combat techniques, making them formidable close-range fighters, and difficult to elude. They have been used since the time of the Greeks and the Romans, where they wore spiked collars and charged against enemy lines, and also saw frequent use during both World Wars.

World War II
The Soviets once attempted to train so-called anti-tank dogs, nicknamed "bomb dogs," to deliver explosives to enemy tanks by diving beneath them and detonating them as they retreated. However, though they were successful in operating in this manner, the plan backfired when the dogs attacked Soviet tanks rather than German tanks. Since the Soviets had used their own diesel-fueled vehicles to train them, the dogs' acute sense of smell was unaccustomed to the gasoline utilized by German tanks.

During Operation Snake Eater, Naked Snake encountered Great Danes that were being used as attack dogs by GRU. Their barking would alert enemy patrols to an intruder's presence and they would also try to pounce on and bite them. Snake initially encountered them at Bolshaya Past South, to which EVA forgot to warn him about the attack dogs presence until about halfway, when he witnessed them. Attack dogs were also deployed in Graniny Gorki's exterior wall as well as within Groznyj Grad. When Snake attempted to escape from Groznyj Grad via the sewers, several attack dogs pursued Snake towards the waterfall at the end of the sewers, eventually being called off by Ocelot himself. There was no easy way to shake them off as they would pick up an intruder's scent, but smoke grenades helped in fending them off. They could also be distracted by meat, although they wouldn't go for Russian rations. The attack dogs also feared crocodiles intensely, and would flee on sight if anything resembling a crocodile (such as someone wearing the Crocodile Cap) was in their vicinity. Despite their large size, they could fit through narrow ducts, as demonstrated in the sewers beneath Groznyj Grad.

Great Danes were also utilized during the takeover of the San Hieronymo Peninsula, this time by FOX and Red Army soldiers. They were sometimes seen guarding areas in the town and were also used during the claymore incident at the hospital, after the soldiers had departed.

Ground Zeroes
Rhodesien Ridgebacks were kept as guard dogs at Camp Omega. When Skull Face arrived at Camp Omega to meet with Chico one last time before conducting his Trojan Horse Operation, the dogs proceeded to bark viciously at him, as they sensed him as being an enemy.

During Operation Intrude N313, German Shepherd Dogs were used to guard areas of Outer Heaven in which no human soldiers were stationed, such as the inner courtyard and basement of Building 1. They were often relied upon to take care of any intruders themselves.

Although not specifically used as attack dogs, the wolfdogs in Shadow Moses Island tried to attack Solid Snake during his mission there. The Sons of Big Boss had originally considered killing the wolfdogs, until Sniper Wolf stopped them. Despite their feral nature, they seem to take kindly towards Meryl Silverburgh when they approach her. They were also suspected to have been descended from wolfdog pups who were abandoned to the wild by various people.

See: Fenrir

Although not attack dogs in the normal sense, the Fenrir Unmanned Gear, mass-produced versions of the LQ-84is, served the same overall purpose, and guarded the World Marshal HQ building's proximity and, during the Abkhazian Coup, preventing the then-AWOL LQ-84i from escaping.

Behind the scenes
In the Nintendo Entertainment System version of Metal Gear, attack dogs are encountered far earlier in the game than the original MSX2 version, immediately after Snake lands in the jungle. This served as one of the reasons why series creator Hideo Kojima disliked the NES version. Unlike the original version, the alert mode will be triggered if the player is detected by the dogs. In the manual, they are referred to as "Dogs of War," which is another word for a mercenary, and was itself derived from a term used in William Shakespeare's Julius Caesar.

Doberman Pinschers are employed within Galuade by the Gindra Liberation Front in the non-canon game Metal Gear: Ghost Babel. In Metal Gear Solid: Portable Ops, the attack dogs can only be found by playing Extreme mode.

Although attack dogs do not appear in Metal Gear Solid: Peace Walker, concept art from the Peace Walker Official Art Works book revealed that they were considered for implementation in the game, accompanying the orange-shirted CIA mercenaries. Their breed, judging by the art, was intended to be that of German Shepherds, similar to that of the original Metal Gear.

In artwork released on a Kojima Productions website recruiting engineers for creating a new Metal Gear game, a dog is seen accompanying Big Boss, who is also shown to be a member of the Diamond Dogs, suggesting that dogs are somehow involved with the group. Whether the dog is intended to be an attack dog is currently unknown.

In Video Data Access File #01000100, also known as the "Sword trailer," there was barking heard in the Army of the Devil's base of operations, implying that they utilized attack dogs while they were in Liberia.

In the opening scene of Metal Gear Solid V: Ground Zeroes, Doberman Pinschers are seen at Camp Omega. However, they don't appear again during gameplay after that, although their presence was implied with one of the soldiers in enemy chatter yelling "shut up, you damn mutt" if the player makes enough noise to have the other POWs hear them. In addition, dogs can be heard barking in Chico's first cassette tape. According to Kojima, he had the dogs bark at Skull Face viciously in the opening scene in order to emphasize that Skull Face was different from the other personnel.