At the very beginning of the game, during a flashback to the protagonist's childhood, he's forced by his abusive father to kill his dog. If he doesn't do it himself, the father will shoot it himself.
A lot of the game's plot revolves around teaming up with a group of mostly Black resistance fighters who are pretty clearly inspired by the Black Panthers. Their leader has a backstory about being framed for murder by the FBI.
Private Wyatt if you choose his timeline has a plot thread about him trying out drugs given to him by a character named J (whom is likely jimi hendrix) however this is an optional thread as if you choose the fergus timeline this won't be there
there is a lot of alcohol use however it appears to mostly be at parties like fergus getting really drunk and Paris Jack's group of anarchists make alcohol
Dog is abused during the beginning of the game during a flashback.
Also mid-game during a flashback, our MC catches a rat in a bucket of water, and it starts to drown. It appears to have died, but it scampers off
The protagonist's father in his childhood segments is horribly racist, and hates the fact that the protagonist has a black friend, using the N-word to refer to her.
The game is centered around the concept that N**i Germany won WWII so antisemitism is a large part of the game and there is a lot of antisemitic hate speech throughout the story.
Nazis are a major antagonist. The game pulls no punches about what a nasty bunch they were. Hitler himself (decrepit, nuttier than squirrel poo, and raving about conspiracies) cameos.
An incredibly sudden (fully clothed) s*x scene is shown briefly inside of a submarine between two side characters. It's meant to be funny, but it's just uncomfortable.