Good feed, plain water, and plenty of space takes care of most things.
Good calm common sense to avoid dramatic conclusions and improper treatments.
I would not store AB's, they have expiration dates,
and administering them them without proper testing is not a good idea.
I got a bag of Corid to treat coccidiosis when I first got chickens, never opened it in 5 years.
A
wire dog crate set up for birds for isolating birds that seem 'off',
observation before treatment is essential IMO.
Good to have some Sav-A-Chick electrolytes/vitamins on hand for dehydration/heat and/or cold stress. Saved a couple birds using that.
Poultry Nutridrench vitamins can be a life saver too, balanced vitamin mix that is absorbed immediately.
Some kind of topical antiseptic for serious wounds, tho most will heal on their own, you probably already have this in your own medicine cabinet..I use neomycin ointment.
Terramycin is one just for ophthalmic issues as other topicals should not be used in or near they eyes.
Qtips for applying topicals, a large needle-less syringe for flushing wounds, a small pair of blunt tipped sharp scissors(nose hair scissors)for trimming feathers around wounds and dingleberry laden butt feathers.
There are several other threads about this...here are a few:
https://www.backyardchickens.com/search/26608949/?q=medicine+cabinet&t=post&o=date&c[title_only]=1
