Yes, some dead seagulls and fishing

There are no dogs in the film

A seagull dies a horrible death by the hands of the mIn character

Seagulls are shown getting kicked and slapped several times.

There are no dogs in the film

There are no horses in the film

There are no cats in the film

No insects but several crustaceans.

There are no dragons in the film :(

There are no spiders in the film

There are no snakes in the film

Alcohol dependence which later turns to lantern fuel dependence

There is excessive drinking of alcohol in this film, and the characters eventually resort to drinking lamp oil.

It's basically a main plot point.

It's not seen in the film

No, but one character is missing a leg & the way he lost it is discussed several times. We never see the leg.

Well, the final scene can be interpreted as torture.

They don't die from it, but there is heavy heavy implication of a character burning themselves and being incredibly injured from it

There is no cannibalism in the film

the head is not shown on screen

There is a story about people losing their teeth from scurvy though nothing is shown.

There is a scene where there's a dead body without an eyeball, it's short but can be triggering.

One of the characters falls down stairs and while no specific bone breaks are shown, it’s certainly an implied consequence

No but there are a few short scenes of the characters peeping on each other through the broken roof/ through the grate on the lighthouse. Super brief and I don't think intentional.

There are a few instances that can be jumpy, but it’s all very minor.

Arguably; characters are infatuated by a mystical “MacGuffin” as a significant plot device, and this influences their behavior in some significant ways, but it’s more obsession than possession. No possession by spirits, demons, etc.

You can definitely hear the gore when someone is hit with an ax

The lighthouse keeper, played by Willem Dafoe, farts a few times in the movie. The first time is even before you first see him. How is that for an entrance?

After a night of drinking, Robert Pattinson's character throws up from his hangover. Directly prior, they wake up to a flooded house and Robert Pattinson is trying to pee into a floating chamber pot

Majorly

While there is no body dysmorphia, there is body horror in the form of weird mutations, and blending of human & animal flesh.

Only if you consider being buried alive claustrophobic.

There is a lighthouse (lol duh) so there is often a rotating light, but I wouldn't say quite flashing.

One character openly gropes himself while berating another. And at one point a character gropes what he believes to be an unconscious or dead woman.

masturbation, sexual imagery

While neither of the characters are canonically gay, there's definitely some subtext that's been confirmed by one of the main actors.

there is no black guy

One character's intelligence is berated often.

Sad isn’t quite the word for it, but it sure ain’t happy.

The two main characters do start to seem like a married couple, where some interactions and conversations could certainly be triggering to someone who has survived an abusive relationship

There are no cars.

Attempted strangulation occur several times.

No hanging, but a character wears a noose around their neck.

The same character falls from a great height twice in the film. First non-fatally, and secondly from the top of the lighthouse and down the stairs.

No one dies by drowning, but a character has visions involving images of drowning.

There are no planes.

There are no cars.

[SPOILERS] This scene is very graphic - we see dirt falling onto the victim's chest and face as he struggles to keep speaking and eventually suffocates. Near the end of the film, you'll see one main character leading the other on a leash like a dog; the live burial happens right after that.