I f you have access to a kosher market you will be able to find there a
frozen product that is pareve (no milk or meat).  It is thawed and then
whipped up just like whipped cream.  sorry I don't know the name of it.
I t somes in a  blue and white container, just  like a small milk
carton.  i t would also be worth checking in a large supermarket for
this.  It is not healthy and it has a metallic aftertaste just like tha
canned stuff but it does the trick.  You also may be able to find
pareve cannned whipped topping at the kosher supermarkets or at a
regular supermarket.  Safeway here( Wash D.C, area) carries a canned
product that would be safe.

Good luck,

Larissa