If the outer shell of the nail has been broken back to reveal the quick, there is usually not much you can do other than clean the wound of loose nail fragments and dirt, and bandage the foot if needed. An effective way to bandage the foot is to attach a clean sock at the ankle with gauze, this prevents any dirt from getting in the wound.
|Example of broken nail that needs to be cut off|
Broken toenails usually happen because the toenail is too long or brittle. Trimming your dog's nails regularly keeps the quick small and helps prevent this kind of injury from happening. If your dog is outdoors and exposed to rocks and other rugged surfaces a lot, dog booties will also prevent these injuries, along with many other foot and toe injuries.