I found most scenes with the dogs distressing because you could feel something would happen with them throughout. Skip 1:30-1:35 at least, when you see Ana and Richard at the table outside and he throws her steak to Freddie. Editing to add: it is also discussed multiple times that the dogs were actually shot to death in life.
For context, the initial scene with the dogs is distressing, but Freddie is having a seizure, he’s not trying to hurt him. The abuse more relates to the relationship between the dogs that Richard does not protect them against.
Throughout, several of the dogs bully Susu relentlessly, which Richard does not intervene in. In the same scene to skip for dog death, just before that, the other dogs attack Susu severely. Skip 1:30-1:35 for the worst part.
Editing to add: it is also discussed multiple times that the dogs were actually shot to death in life.