Re: Well ...
This is why pen and paper is so good. I'd have had a portable printer pumping out mini vacc certificates.
When I was farming we had old-fashioned paper log books for the herd. For certain things, the cow's tag # was entered into the book. Somewhere else, there as a line pre-printed for each cow (again based on tag #) and as the vet did the job the appropriate item was marked in the book by the stupid kid roped in to follow the very around all day taking notes (not that I'd know who that kid was, no not me, honest! :) - though I got to spend some quality time with the vet learning a hell of a lot more about herd health then the farmer could ever teach me)
With some jobs, we actually just used a paint marker that'd wash/rub off in a few days/weeks. At the start of the mating season a marker that'd rub off was also used to tell us which ones the bull had met with.. If Mastitis or other issues were detected with the udder/teats (including cuts or other sores), a red marker was applied so her milk couldn't go with the normal lot until she was healed. Using the paint was quick and simple, and would last plenty long enough so if the vet lost the logs on the way back to their office or the office burnt down the following week etc, we still could just look and see which cow'd had what treatment.
Nice to see even today computer's aren't as reliable as a can of Dazzle :)