I have a recommendation for anyone wanting an impression of their pets feet/paws/hooves/etc! I picked up a product by the company Pearhead. The one I purchased was actually a baby hand print impression kit but worked wonderfully for my dogs paw. They sell kits that are actually supposed to be for pets and also picture frame/impression combos on their website. The kit contains a non-toxic soft clay like foam that you roll out and press your pets paw into. I found it leaves a much more clear and detailed impression than plaster does and it is far less messy! You can check out the products on the website and I also found some more by just doing a Google search!
I will actually be getting a tattoo from the impression I did of my dog who recently passed away. Once the foam had dried for a few days (it does get slightly hard, but not completely) I stuck it in our copier on our printer and it copied beautifully onto paper!