The only things we have are dog painkillers from the vet and a first aid kit containing the usually bandages and tape that kind of thing plus anything else i can get from work. One of the advantages of being a student nurse is you have access to all kinds of dressings.
The OH goes out biking and takes Diesel but nothing bad has happened to Diesel yet, I always assumed a normal first aid kit would be enough until he could get to a vet but you raise a good question.
I keep a doggy first aid kit in the car and another one at home, they contain: vet wrap bandage, conforming bandage, wadding/padding wrap, a roll of cotton wool, plain bandage, non-adhesive sterile pads, tweezers, a syringe (for flushing wounds) saline solution, sticky plaster tape, scissors, a tick remover and a spare slip lead.
The one at home also has vet powder, hibiscrub, and some assorted lotions and potions which I won't list as they probaly shouldn't be in there
If an injury needs more than I have in my box I would be straight off to the vet as it would be beyond my capabilities, both in what I have to hand and my knowledge to deal with it.
Forgot to add, Di oranised a first aid training eve a while back which I attended and I learnt a lot, a very worthwhile and informative evening.
I have a first aid kit for Kaiser. Apart from that i always make sure we have Piriton in case his allergy kicks off and some gauze wipes. We did have hibiscrub but have run out so will probably invest in some more just in case. All the rest is his usual stuff like flea and worm treatment.