i'm confused. i don't see the source at all...
your animals are kinda distorted. and...well...the shadows are wrong. correct me if i'm wrong, but did you use the source image.

No use of source image, animals are distorted, shadows are wrong.

I used source image , cat is at bridge up on wall ... Yea shadows are wrong =) First time doing them xD

a bit awkward

Your source image is hard to see, the dog is too distorted and the shadows don't match but a good idea.

Dog and cat running are distorted.

sorry but all is wrong

I think this is funny, and I do see the kitty up on the bridge. Shadows are pretty easy if you know the tricks. Don't give up. Here is a link to a tutorial on shdows.
http://www.photoshopcafe.com/tutorials/cast_shadow/cast_shadow.htm
Hope it helps.

Thank u Emik =)

I like ur colors effects always.

Thanks xD

I'm not sure why you changed the perspective of the original dog and cat? You could have easily kept the perspective and just flipped the cat horizontally and everything would've looked a lot better. Better yet I would have kept the original background of the dog, added the cat and then pasted the source cat on the new cat. Here is a quick example. http://i67.photobucket.com/albums/h302/Chalty669/example-1.jpg