My dog scratched his cheek open and it's bleeding. Should I see a vet?

Poor Harley. From the picture, I'm concerned about the depth of that wound, and I wonder if she was bit. Dog bites frequently become infected. I do think you should take her into a vet to get this treated.

Yes, it looks just like some sort of wound from an injury. I would not be overly worried about it at this stage. You can use this wound spray 3-4 times per day and if after a week or so it is not looking better then she should see your vet. https://www.petco.com/shop/en/petcostore/product/vetericyn-plus-hot-spot-antimicrobial-gel-for-dogs

Intense itching like that is usually due to allergies or mange. In order to find out the cause, you'll have to take him to the veterinarian. I'm surprised that the nails would bleed from scratching the chin. I would expect that the chin would bleed before the nails do, so the nails may have been hurt some other way. For now, rinse the skin with cool water for 5 minutes twice a day. This will help give a little relief and help prevent infection.

No need to rush Sheru into a vet now. I would gently clean his wound with warm water and antiseptic soap. Keep the wound clean and dry, and monitor it for signs of infection. If you see redness, swelling, warmth to the touch, or pus, then it is infected and he will need to see the vet for antibiotics to treat it. I hope this helps!

It looks large enough it may need stitches but to do that at this point they would have to make it larger to get to fresh edges. You can keep it packed with neosporin but will likely need an e collar to keep him from scratching it again and restarting the healing process. I would see a vet to see about surgery or at least antibiotics to let it heal on its own

Poor Achilles! I would stop putting peroxide on it, as it actually damages tissues and interrupts the healing process. It sounds like this spot is really itchy to him, and it could be caused by fleas, mites, ringworm, or allergies. If he isn't up to date on his flea treatment, he will need a spot on treatment such as Advantage or Revolution. You will need to disinfect the environment as well. If he is up to date on his flea treatment, I recommend taking him into the vet for an exam tomorrow. The vet can do blood tests, skin scrapings, and use a Wood's lamp to diagnose allergies, mites, and ringworm. Once the cause of the itching is found, the vet can prescribe the appropriate treatment.

It looks like what we call a hot spot or moist dermatitis. These looks really painful. I would have him seen. He will most likely need some antibiotics and some topical medication to help dry this up. They can also give you something for the itching or pain relief. These usually heal pretty quickly once they stop messing with them.