Saline solution is also good for rinsing out a wound.
We have a generic first aid kit for the trailer but keep different 'kits' here for the - gawd I hate to say it but normal stuff!
We have -
bandaging kit - assorted bandages, tape, vet wrap, betadine, antibiotic ointment, saline, fly spray & swat, empy syringes, bandage cutter, thermometer
eye kit - saline, antibiotic eye ointment, syringes, acid water (alternative vet product), baby wipes, fly spray
colic kit - pepto, mineral oil, syringes, empty child size enemas, gatoraid type product, (for foals pedialyte), senna, nex vomica, simethicone drops (infant gas drops),
buscopan and banamine (both types), thermometer, probiotic paste/powder
general - flashlight, miner's head light, box cutter, rubber gloves, garabage bags, baby wipes, betadine wipes, nolvason and a container to mix it to 10% strength,
tubs of vaseline from the dollar store (one horse/use per tub its to cheap to use contamined product).
We also have a foaling kit and my 'bucket' for farrier visits (dewormer, extra syringers, ziplock bags/markers for mane hair pulls, scissors, pen/paper for notes, saline and baby wipes for cleaning eyes/noses, antibiotic eye ointment, treats (baby carrots), bottled water
Buckt with lid - assorted clean rags, towels and a sheet.
I know there are other things but that's off the top of my head (lol), I just this year made up the individual kits into clear plastic kits with lids so they can be easily identified and carried.
On the rare occasion we have multiple 'patients' we make up individual kits for each based on what is going on. The worst time - 2 different leg injuries requiring daily bandage changes and meds, a colicy horse, and an eye injury. Felt like a vet hospital!!!!
Dollar stores are great for many products as is Walmart or other super store. Some human stuff is cheaper than the equine version so check. We found that out with the leg injuries that non stick pads and tape were cheaper at Walmart than any vet supply and easier to get! Same goes for pepto off brands, vaseline, zinc oxide, etc. I buy a few pepto/vaseline every year at $1.00 each and if I toss them it's still cheaper than not. I've seen people buy the gallon of bismuth subsilicate (sp?) pepto generic and it sits for years - ugh! How good can that be?