You don’t see a dog being killed, but there is a conversation in a restaurant overheard and apparently this guy likes to kill dogs and then she goes into a bathroom and there’s a dead dog in the toilet. It does not look real.
One of the main characters family has their pet dogs that died taxidermy in the house. Also, there’s some kind of dead canine in the toilet when she goes to use the public restroom while they are traveling. It doesn’t look real, but it’s disgusting. She overhears a conversation right before that where they are talking about why this guy has so many missing dogs.