Hi  I'm leasing a horse.  Back in the saddle again after 29 yrs.   I have bought a horse trailer & was wondering what should I stock in it.  lead ropes?? how many?? fly spray etc etc.  I will be trailering her to local shows.  How much water should I bring or do these shows have a place for a horse to drink????

Langley BC

It's really a matter of preference, but here's what I can remember is in my trailer DR:

(2) halters, (2-3) leads, 2 girths, (2) saddle pads, several buckets, (2) 6 gallon water containers, hay bag, saddle bags, 2 bridles, lots of bailing twine, trailer ties, fly swatter (horse hair tail), fly mask 

various meds, brushes, fly spray, bungee cords, hoof pick, 1st aide kit, sponges, stethoscope, bute & banime paste, leg wraps, vetwrap, hand cleaner, hoof picks

duct tape, hammer, spare tire, various lengths of rope, branch clippers, broom

during camping season: tie-out rope, tree savers, fold up chairs (2-3), small table, porta-potty, tp, fence poles for electric paddock, fence tape & charger 

 Rear tack: manure fork, tarps to cover trailer tires when using trailer 

What Dunoir said plus,

Hose, blocks for trailer tires, padlocks & chains, insect repellent (for humans), meat tenderizer for bee stings.

I bought a big tool box and stocked it with what I'd need at a show- brushes,fly spray,show sheen,a lead rope, halter, a bunch of clean towels,bottle of shampoo......etc. I leave that stuff in the trailer so I am ready to go. Don't get to cluttered- sometimes I pack so much stuff I forget what I have. After a few shows, you'll know what you do and don't need. Extra stuff is ok but be realistic about what extra things you'll really need. I can see a extra lead and halter but you can over do it getting two of everything ( not to mention that can get expensive) Think about packing a few first aid items but again, not so much it gets cluttered. Keep it simple.