Technically in one of flashing scenes there are multiple dead animals shown, including a dog, but it’s extremely brief to the point you aren’t sure you saw it
There is a brief image of a needle with its plunger being pushed down during a sequence of flashing images. During a flashback, a character is shown with an IV in their arm.
::::This is a really bad movie for people with sensitivity to strobe effects::::
They occur immediately in the opening sequence and periodically throughout the movie, often after the song "Beautiful Dreamer" plays but sometimes with no warning.