1. Flashlight
  2. Thermometer
  3. Clippers
  4. Mild soap : Ivory soap & Antiseptic: Betadine® solution
  5. Sterile saline solution for wound flushing
  6. Tweezers (to remove ticks and/or splinters) and scissors
  7. Wound cream or ointment (Neosporin®, Biozide® ointment, etc)
  8. Bandage Supplies (gauze, cling, roll cotton, brown gauze, Vetwrap®, Elastikon®, duck tape, adhesive tape)
  9. PVC pipe (several different sizes) for splinting leg injuries or fractures
  10. Phenylbutazone (Bute) or flunixin meglumine (Banamine®) for anti-inflammatory and pain relief

More info here.