You were grooming Sparky, and he jerked his paw at just the wrong moment. In an instant, you clipped his nail a bit too short, and he's bleeding. Don't hate yourself; it happens. You can treat the injury with items you should already have in your home already.
Stopping the Blood Flow
The live tissue and blood vessels in Sparky's nails are commonly called the quick. If you nick the quick, don’t panic. Offer treats to keep him calm and distracted. If you have styptic powder, use it on Sparky’s nail. Otherwise, step into your kitchen and get flour or cornstarch. You should need to place only a small amount on Sparky’s nail to get the bleeding to stop, but you may have more luck putting the flour or cornstarch into a bag and putting his paw in the bag. Regardless of the method you choose, stay calm and help keep Sparky calm. High blood pressure will cause the dog to keep bleeding if he is stressed or running around.
If you can’t get Sparky’s bleeding to stop, take him to his veterinarian immediately. Even if you stopped the bleeding, you must monitor the dog. Check his nails and toes for swelling, redness or pain, which can indicate an infection.