What is this little red ball?

If you have ticks in your yard or have found some on your dog most probably it's the head of the tick (no body)that got embedded in the skin and it beame infected.If he did have a tick and you pulled it out or he scratched it out either way that's a good way for a tick to leave the head part imbedded.pour some peroxide to cleanse the wound some blood may come out by the way that red ball is a glob of blood under the skin.