Keep an eye on it
What it can look like. A general, vet-reviewed example — signs vary and this is not a diagnosis. When in doubt, ask your vet. 
Scratch wounds in dogs
Clinical name: Excoriations
Raw, broken skin and scratch marks from the dog's own claws.
Where it shows upgeneralized
Typical patternWherever the dog can reach.
Linked allergy typesFood allergy · Environmental (atopy) · Flea allergy
Food vs environmentalNon-specific (itch-driven).
What you can do
Broken skin can get infected — keep it clean and see a vet if it spreads.
Don't confuse it with
Other causes a vet will want to rule out: self-trauma from pain.
This is educational information, not a diagnosis or treatment plan. Always see your veterinarian about your dog's health.
Related signs
Hot spotsSee your vet
A moist, red, oozing and painful patch that appears fast, with hair loss over it.
Pus-filled spotsKeep an eye on it
Small pimple-like spots with a white/yellow head.
Crusts & scabsKeep an eye on it
Dried serum or blood forming crusts and scabs, often where the dog has scratched.
Flaking & dandruffTrack it
Dry flakes in the coat and a dull look to the fur.