BLACK ELECTRICAL TAPE!!!
If it's just a one-day show, you probably won't need the following, but if it's a multi-day show it wouldn't hurt:
Bute
Ace and/or banamine
(just in case)
For the Trailer/ Tack Stall
Buckets
Hose
Fly masks (to protect their eyes from debris while trailering)
Hay
Muck fork
Broom
Water container with water from home in it (you can mix it with the show water, and they'll drink it - - also, you can add peppermints to their water at home and add them at the show )
Shipping boots
Extra lead lines
Bailing twine (to hang buckets)
Bleach (if it's a dirty stall - just scrub it down!)
Extension cords
Sweat scraper
For the Rider:
Clothes
Make up
Mirror (!)
Brushes for your hair
Safety pins!
Gloves
Hat
Whip/ spurs (if you use them)
Shoe polish
Bobby pins
Hairspray that holds like glue
Umbrella/poncho
For the horse:
Coggins - a definite around here!
Cooler/ sheet
Treats
Hoof black/ hoof white (we show saddlebreds - - white foot = white shoe polish (then let dry) and paint over with clear)
Show sheen/ baby oil
Vaseline for the face and ears
Lots of extra rags
Tack - always bring 2 saddlepads in case one gets dirty (if it's white)
General first aid ointment
Fly spray
Brushes
