Dogmeat

Dogmeat is an NPC in Fallout 4.

Dogmeat Information

Dogmeat is a German-Shephard Dog.

Can be recruited as a Companion.
As a companion, his natural Affinity starts at maximum and is utterly loyal. Your choices do not affect his feelings for you, and his companion perk Attack Dog is available from the start.
Will track Kellog through the scent from his cigar in the quest Getting a Clue.

How this character responds to your choices

Name	Generous	Selfish	Nice	Mean	Peaceful	Violent	Chem Use	Chem Addiction	Donating	Alcohol
Dogmeat	-	-		-	-	-	-	-	-	-

At high Affinity the following perk unlocks for you:

Companion	Perk	Effect
Dogmeat	Attack Dog	Your faithful canine companion can hold an enemy, giving you a greater chance to hit them in V.A.T.S.

Name	Level	XP	HP	DMG Resistance	Perception	Abilities	Items

You can have the Lone Wanderer Perk and still use Dogmeat with its benefit.
When you dismiss Dogmeat to Sanctuary Hills, you can find him again in one of the doghouses usually. If you can't find him, sleep or wait until night time and check the doghouse (note: you can not find him there if you scrap all the doghouses)
If the dog still doesn't appear, make sure it isn't on the roof. If it is, build stairs to the roof. (Known Bug)
Also, if you cannot find him at all, use the following (on PC):
Open the Console by pressing ` (same as ~ on US keyboards)
Type: prid 0001d162
Press: ENTER
Type: moveto player
Press: ENTER
That will teleport him to your current location.
He's usually behind the first house on your right when you cross the bridge into the town, the one next to the sign. There's already dog house there.