Dogmeat is a player companion in the Fallout series. He gained his name from the post-apocalyptic movie, 'A Boy and His Dog'. The dog in the movie the accompanies the protagonist, is called Blood, but at one point, the boy refers to him as Dogmeat.
Dogmeat also makes another reference to a movie, Mad Max, which Max has an Australian Cattle dog. This is the same breed that Dogmeat is.
Dogmeat will join you in the first two games regardless of Karma.
Dogmeat can be located in the town of Junktown. He blocks the entrance of a home and the owner asks you to deal with it. If the player wears a leather jacket or feeds Dogmeat, he will join your party.
It is considered canon that Dogmeat died in the force fields of the Military base.
Dogmeat can be recruited only after a special encounter at the Cafe of Broken Dreams. Dogmeat will join your party if the player is not wearing any armor.
You can find Dogmeat southeast of Minefield at the Junkyard. You will have to save him from a few Raiders before earning his companionship. Once he has been added as the player's companion, the player can tell Dogmeat to go back to Vault 101, stay, follow, or find weapons/ammo/medicine and chemicals. Additionally, Dogmeat will occasionally attack enemies causing his health to decrease. Players can heal his health by giving him stimpaks. If Dogmeat dies there is no way to get him back.
Fallout 3 DLC: Broken Steel
In the 'Broken Steel DLC' a perk can be gotten at level 22 called Puppies! If you enable this perk Dogmeat is reincarnated as a puppy every time he dies and can be added back to your group either by finding him resurrected at the location of his death or by waiting until he is moved to the Vault 101 entrance. Dogmeat's puppy seems to be much tougher than the original Dogmeat.
Despite the name, this perk only allows you to get one of Dogmeat's Puppy at a time. If it dies, it will be replaced by a new puppy. This perk still works if Dogmeat died pre-Broken Steel.
Sometimes reported as a bug, Dogmeat's health if recruited with Broken Steel increases by 2,000 as opposed to normally 500, and increases as the player levels up.
Dogmeat's Puppy is visually the same, but has a new name (Dogmeat's Puppy), and some of the dialogue available with it refers to it by different names (such as boy) has double the health (1000) of the original Dogmeat.
It uses the exact same ref and base ids, upon death Dogmeat is simply respawned with a new name and increased Health effect added.
A good way to get XP and Bad Karma is by killing him over and over again.