No real takeaway other than that dogs should be treated nicely.
Dog fighting is implied, rather than shown, but there's plenty of it -- lots of offscreen mauling is supported with audio elements, with dead or badly wounded animals shown afterward. A dog is shot several times on-screen; others are tortured and murdered by humans just off camera. There's a fair amount of blood. Several humans are killed by a dog; two people are shot, and one is punched. One dies of a drug overdose.
Nude pinup photos on a wall; they're shown prominently (and interacted with) in one scene.
Frequent strong language. "F--k" is used in place of most adjectives. Also some use of "s--t" and other words. None of the language is used for emotional/graphic effect.
One character is an opioid addict; he dies via overdose. In flashback, viewers see an abusive father drunk.