My CAPS!!! OH NOES!!!
Please, and I've said this to a whole lotta people, optimize your sound. As a South African, you must understand that every megabyte of cap is PURE GOLD! T___T I've just downloaded three full songs to watch a movie that should've been no bigger than 1MB.
Anyway, on to your animation! :D
Great use of music; it really heightened the atmosphere! And a fun motage of the party, too! And the character design of the dogs is adorable - I was smiling at their cuteness the entire time.
Also, Flash is ACTUALLY man's best friend, and has great smoothing with its drawing tools. It's unnessecary to "sukkel" with Paint and then having to import it, erase imperfections and all that. It's a lovely time saver.
Other than that, great fun! And what a sweet story, too! (Poor dogs, though) :3
Can't wait to see your next creation! ^^