I’m going to say no with the caveat that it’s unclear if there is a dead dog shown at the end, after they’ve escaped the room and entered the outside where there’s barking. It was too dark for me to see anything, so certainly if there was supposed to be a dead dog, it’s not obvious or a huge thing. However, there are pairs of dogs ‘sewn together’. Whatever they did to create that effect, it didn’t look gruesome, it just looked like two dogs close together with some blurring in between.
Nothing is shown as happening, but pairs of dogs that are ‘sewn together’ are shown. You don’t actually see anything to know that without the context from the rest of the film; it looks like pairs of dogs close together with some blurring in between.
Again, no, but with the caveat that there may have been and it was too dark to see. It would be once they left the room and went to where the barking was.