A bleeding injury can be quite frightening, and even a small amount of blood can seem like a lot when it is smeared around. Your dog can suffer a bleeding injury if he is bitten by another animal or hit by a car, if he steps or falls onto a sharp object, if he breaks off a toenail, or from myriad other forms of trauma.
As scary as the bleeding may be, you must first assess his overall condition. Is he alert and responsive, or does he seem disoriented from his injury? Is he able to stand and walk normally, or does there appear to be damage to his limbs? Is he breathing normally? Is the blood seeping slowly, as it would from a cut on your own skin, or is there rhythmic spurting that might indicate a cut artery?
If the injury appears to be more than a simple bleeding injury, call a veterinary hospital for emergency advice, and arrange for immediate transportation. Some simple bleeding injuries, such as a torn toenail or a cut foot or car flap, should still be examined by a veterinarian, but do not require drastic emergency measures.
Clean the wound with copious amounts of warm clean water, then apply light pressure to the site with a clean dry towel. If the bleeding continues, or if the wound is the result of a bite, take your dog to your veterinarian.