Advance Directives are state specific so you can check with a Council on Aging or whatever state organization you have. You can also google advance directive for your state and some options should show up. Some states have separate Living Wills and Health Care Powers of Attorney and some have combined forms with selections addressing both situations.
A big difference can be the signature and witness requirements that vary by state so I would use the one developed by my state. I know there are some generic ones, but for practical reasons, I would use the one best known by and familiar with my medical providers.
If my dog doesn't like you, neither do I.