Interesting
I couldn't help but sense that there was a war allegory in this flash. You really seem to be trying to make a statement, but until I see the rest of this animation, I don't know what that statement is.
The black and white worked well, and made a good contrast to the blood, making everything very stark and surreal.
I do think you could work on your realism a little. The cats and dogs were rather misshapen in some scenes. Over all, very well done.