Dog (Fallout 4)

Dogs are animals that can be found in Fallout 4, and act as companions towards humans. While the different breeds that may be in-game are possibly unknown, this one being a german shepherd is confirmed to be the companion to the Sole Survivor as seen in the end of the trailer.

Background
Most commonly seen as feral beasts that plague the wastes and kill livestock, they are necessary for many struggling wastelanders. There is also the rare cases of domestic breeds that act as companions towards their human counterparts.

Humans are the only species known to truly tame and domesticate these canines. Although other types of sub/meta-humans show an interest in doing the same, dogs of all types, including feral dogs, are well-known to attack or flee from them on sight.

Biology
Through the 200 years since the Great War, dogs have remained relatively unaltered by radiation, seemingly a miracle. Other than that, there is no reason to believe that the biology of dogs in the Fallout universe differs from dogs in the real world, besides having a rougher appearance than domesticated dogs, unsurprising in the harshness of the Wasteland.

Notable dogs

 * Dogmeat - companion of the Sole Survivor.
 * Junkyard dog - Possible purchase via a random encounter with the dogs owner/ breeder, Gene. The Junkyard dog is not a companion but rather, assigned (like a settler) to any Settlement. When the dog arrives the designated settlement receives 5 Defense rating buff. Looks like a Rottweiler and as a level 1, has 180hp so most likely actively defends the settlement also.
 * Mutt - aka Sparky, aka Buttface, is a random encounter where you can approach a wounded passive female (Lone survivor refers to her as "girl") mongrel. Her right legs are at 0 health if you check VATS. You can interact with the Mongrel and will be given the dialog prompts to ask if there is anything wrong and then a second prompt to render help will be available. Afterwards the right legs will be at full health in vats and the mongrel will walk normally. The third dialogue prompt has you either ask her name or choose between 3. Mutt, Sparky, Buttface.  If you ask her name instead of picking one she will then be labeled "Mutt" afterwards. After the naming dialogue concludes Mutt will simply stay in the area until the encounter/zone resets. Encounters confirmed to happen at the courtyard/statue across the street from Arcjet systems, under the railroad bridge just south of Starlight Drive in, and in the partially destroyed house just west of Outpost Zimonja.   Having Canned dog food and/or a dog collar in your inventory has no effect on the encounter. Mutt will follow you around within a relatively large area if you don't walk too far away.  The encounter at the Starlight under the Railroad bridge will have Mutt follow as far as the restaurant overhang at Starlight.  You cannot assign or interact with Mutt in "V" or build mode like you would a purchased junkyard dog. Mutt will not interact with a dog house if placed.  Pickpocketing a dog collar into Mutt's inventory won't have any effect.

Appearances
Dogs appear in Fallout 4.

Hund (Fallout 4) Pies (Fallout 4) Псина (Fallout 4)