1)A RECTAL THERMOMETER. Yes, rectal. Digital thermometers are best because they are a) unbreakable, and b) faster.
2)SALINE SOLUTION-- To flush your pet's eyes, or to irrigate a wound. The easiest source? Your local drug store, where you can find squeeze bottles of saline designed for use by human soft contact lens wearers... like me.
3)A PAIR OF HEMOSTATSor other tweezers, for grabbing foxtails, fishhooks, etc.
4)ANTIBIOTIC OINTMENTfor the inevitable skin wounds
5)GAUZEfor dressing those wounds
6)BANDAGE MATERIAL-- preferably a "No-Chew" version. And no, Ace bandages are a poor choice for pets.