The sound could use some work
The sound is too dry. Some echo or reverb could make this so much better, give it a bit of depth.
I know it can be hard to think of ideas for animations, but why does everything round here end with people or animals getting killed? It's a cheap pop as a large wrestler might say. Is a horse getting shot funny? Not particularly. Are most people that visit newgrounds 13 and think killing animals is funny? Yes.