Check lists for trailrides and shows.

Truck/Trailer

Auto club membership, towing insurance, or other arrangements for emergency road service that covers trailer and tow vehicle.
Basic toolbox
Coggins tests, health papers, and any transport papers required for horses.
Extra flashlight batteries
Fix-a-flat or air tank
Fire Extinguisher
Flashlight or shop light
Jack or lifting device
Jumper cables and tow chain.
Keep emergency contact info in truck, include your name, address, phone, names of emergency contacts and any drug allergies you may have as well as current medications you are taking.
Lug wrench
Registration for both tow vehicle and trailer, with current inspection stamp; insurance card. (maybe keep a copy stashed in the trailer)
Road flares or warning signal in case of breakdown.
Roadside emergency markers
Spare tire
Tire-pressure gauge
WD-40 or similar lube
wheel chocks or Blocks (two) to put behind front and back tires when parked (the type of block that can serve as a ramp for changing a tire is especially useful).
Work gloves and waterless hand cleaner
Dog Tag travel halters - incase a horse were to get loose - also good for trail riding.

"HUMAN" First Aid

Antibiotic ointment
Baggie of band-aids and towelettes
Bandanna
Can of bee/wasp/hornet stun spray
Clear bandaging tape
Eye pad
Forceps & tweezers
Insect sting swabs
Kleenex
Pocket first aid kit
Rolaids
Scissors
Sewing kit
Tylenol
Zinc oxide ointment
2X3 gauze pads
12cc bent tip catheter

"HORSE" First Aid Kit

2x2 gauze pads
36" latex bandage
12cc syringe w/o needle
Ace Bute, Azium, Dipyrone & Banamine
"B-KALM" paste
Cardboard (makes hoof plate if horse steps on a sharp object.
Cotton Gauze
"CUT HEAL"
Disposable razor for clearing hair away from a wound.
Duct tape
Electrolytes
Furazone, Betadine scrub or Iodine.
"FURALL" spray
Hoof Pick w/ brush
"KLING" dressing
Leg wrap
Needles & syringes (learn how to use them before an emergency comes up)
Nitrofurazone ointment
Oral syringe
Phenylbutazone ("BUTE") tabs or paste
Scissors
Small rubber bands
Sponge
Stethoscope (learn your horse vitals so you can compare them with stressed situations)
"SWAT" fly repellant ointment
Thermometer
Tube sock with the end cut out (makes a good leg bandage that can be rotated and used for several days)
Tweezers
Twitch
Velcro straps
Vet wrap

Toolbox:

Crowbar (essential in case you need to remove center divider quickly).
Electrical tape.
Extra bulbs for trailer lights and extra 20-amp fuses.
Extra quart of oil for tow vehicle.
Flashlight and extra batteries.
Screwdrivers, pliers, hammer, wrenches, and so on.
Sturdy knife (to cut tie ropes in and emergency).
WD-40, grease, or lubricating oil.

Equipment:

Blanket (for higher elevations)
Brand inspection certificates (required if crossing state lines)
Brushes & Hoof pick
Cinches & hammer
Dental floss (Good for dental hygiene and can be used for repairs)
Equine health certificates i.e.: negative coggins (required if crossing state lines and in some locations and national parks)
Easy boot (one to fit every horse)
Electrolytes Salt (in tube form is nice)
Electronic fence (less stressful than tying)
Extra girth, bridle & pad
Extra trailer ties
Feed & water tubs
Fly mask
Fly spray
Girth covers
Halter Id tag (good if your horse gets loose)
Hole punch
Horse water (I try never to use public watering troughs)
Leather thong
Leg wraps quilts & shipping boots
Lunge line
Lunge whip
Picket line or hobbles
Pliers
Rake & carrying container for manure removal
Saddles, pads & blankets

Misc. list

Ample personal clothing Dress in layers
Aspirin
Benadrill (helps with stuffy noses & bug bites and stings)
Campfire permits
Camp stove
Can opener, bottle opener, cork screw device
Canteen or water bottles
Chap stick
Charcoal
Cell phone
Dish pan
Duct Tape (fixes everything)
Extra batteries
Flash light
Food
Gloves
Ice chest
Lamps
Matches, lighter fuel , candles
Needle nose pliers
Paper towels
Plates & utensils
Regular shoes
Riding shoes
Pocket knife
Road & trail maps
Sewing kit
Sleeping bag pad or cot
Slickers
Small tarp
Soap scrubber
Sun screen
Sun glasses
Table & chairs
Trash bags (good for lot's of things)
Wilderness permits
Small towel bandanna
Walkie-Talkie Radios
Whistle
Wire cutters