Anyone know where I can find a bvh file for a 4 legged animal such as a dog or a cat?

I have plans for use of this in Second Life

You have to make your own by posing the SL human avatar figure as a quadruped. YOu can purchase bvh files for animal figures, but they will not work in SL.

If you want a quadruped animation just for your own use, you can take an animation from an avatar that is mod/copy/no transfer. The Dragonlet avatar in the SL Library has one of these animations. However, you won't be able to sell it or give it away to anyone.

I have found animating quadrupeds using standard animation programs (DAZ, etc.) almost impossible to get right, since you are working with a human avatar form that has the wrong leg and arm proportions. Does anyone have any suggestions to make it easier?

actually I need it for poser. And not on a human. I am creating an animated sculpted animal. I should of been a bit more specific. I'll put up another thread asking more specifically.