At the top, I put the animals name, its birthdate (if you know it) and when you purchased the animal.
On the three columns, I label them Vaccinations. Worming. Shoeing.
You can easily make more columns if you need to, for breeding/foaling, etc. or whatever you need to keep track of. I give each animal their own manila folder, where you can keep this permanent record as well as papers, vet receipts, or whatever else you need.
I use this system for cats and dogs, too, and I label the columns Vaccinations. Worming. Flea Treatments. And for my donkeys, I just change the Shoeing Column to Trimming.
This system works so well for me I thought I'd share it. There's nothing worse than having to flip back through your calendar to try and find information, and if you have lots of animals, it can get confusing.
Probably those of you with big stables may have a white board up in the barn, but this is a simple method to keep those records in the house, and if you ever need a copy to give to the vet, it's all right there.
Do you keep good records on your animals? Any other tips to share?