Bursted pimple that left a deep hole...

My husky had this blister like thing above his green line tattoo, and it popped. It started gushing blood. And it doesn’t really look like it in the pictures but it’s a pretty deep hole. I can’t see the end of it. I held a cloth over it until it stopped but I have no idea what it could be. It was clearly hurting him, he was whining when I touched around it. It’s also the size of quarter. (Not the hole, but the diameter of the entire thing including the swelling.) What could this be and what should I do?

Ouch, that looks really sore! That looks like an abscess - quite likely due to a thorn or other foreign body, although we do see those without anything in them too. Strictly speaking, the best thing to do would be to get it flushed out by your vet, to make sure there isn’t any pus, infection, or splinters left inside. In the meantime, keep it clean and if possible, bathe it with salt water to prevent the infection becoming established. Ignore the advice to apply antibiotic creams unless your vet recommends that - in open abscesses like this they often cause more harm than good.