The items (beyond what I use for people) is:
1. Rabies/vaccination documents (I keep a copy in my daily vehicle and my RV at all times - just in case)
2. Tick tweezers - they work opposite other tweezers/pliers in that when you squeeze they open, that way you can clamp them on the tick and then turn without trying to keep them tightly closed.
3. Horse leg wrapping - it's self adhesive and works to wrap around large body parts, etc.
4. Extra collars and leashes - never know when one will break, etc. I also have a dozen of the groomers' style noose leads.
5. Tie out stakes and cables.
6. Small ID tubes, similar to the old barrel style ones. I can write our campsite, vehicle license number, dates of our stay, etc. on a small piece of paper and then insert it into the tube. I use a dab of crazy glue on the threads when I close it (so it doesn't come undone). When I move to another campground, I switch out the paper.