Reiterating what has already been stated -- be aware of your dog's health limits. If they came up lame miles from the trailhead, how would you carry them out?

I've had some conversations with Gidget's vet about what should be in a First Aid kit for her and among the critical items:

Benadryl (1 mg per pound of dog -- in case they're stung or have some other allergic reaction. Benadryl does not make dogs drowsy.)

Gas-X (if you even suspect bloat, give it to them)

Buffered Aspirin

Bag Balm (paw pads)


Longer list (for home and car kits)
http://www.paw-rescue.org/PAW/PETTIPS/DogTip_FirstAid.php