If you are a professional in the area of helping stray animals, then you already know what to do. It is still wise to be on the careful side. If you find a stray dog or cat that has not been hit, remember it is still a potential danger to you. Cats, in particular, can be ferile. You can put yourself at great risk in this instance.
Dogs can have rabies.
If you are bitten, immediately contact your local emergency room and your local doctor. If you do not know the dog and it has not been tested for rabies, you will very likely have to go through a series of rabies shots to avoid a worst case scenario. Even a friendly looking animal might be very scared of a human, and this can spark aggression. These are the worst-case scenarios, of course, but it is always better to be safe than sorry. Always be gentle with a stray animal.