Uhh...
The animation was great... But the humor wasn't really all that funny.
The only thing I didn't see coming was in the beginning when he went into the first dog. Everything else was pretty much obvious.
The guy getting shot didn't even yell or anything till the end.
Maybe:
He could have entered it through the mouth.
Longer
There really wasn't any build up. Just punch lines.
It also makes no sense. Why did he get in the dog in the first place?