Lou Ann is right! And we used to do that...we'd always have some on hand. Now the Vet gives us a Rx for some to have on hand for an emergency, or especially if we're traveling. With directions of dose and weight, and what drug to use for what type of injury.
If you have a good relationship with your Vet, ask for an emergency kit list, and for Rx's that you can get filled to have on hand in that kit. Most will do it if they know you. And also when traveling, get the phone number and address of the Vets in the area you're visiting and have it handy ... just in case.
Also always take proof of Rabies vaccinations with you (I take a copy of the certificate), and a list of most recent vaccinations (ours are on the Rabies certificate, at the bottom).
Plus a note for who to contact in case something happens to you. With names and phone numbers, and a notification to put the dog into a boarding kennel, and do not take it to a shelter, that the person named will be responsible for any charges incurred . Add the dog's microchip number to that paper.