Dog Health • Skin

My dog has a hot spot. What causes it?

A hot spot—acute moist dermatitis—is a rapidly inflamed, moist, painful area created by intense licking, chewing, or scratching. The trigger behind the self-trauma matters.

Veterinarian reviewedUpdated Aug 20, 2026
The key takeaway

Hot spots can enlarge within hours. Treatment should address both the damaged skin and the reason the dog started scratching.

Common triggers

Fleas, allergies, ear disease, trapped moisture after swimming or bathing, insect bites, matted coat, and local pain can start the itch–lick cycle. Thick-coated dogs may hide a much larger lesion under the fur.

What do they look like?

Typical lesions are red, wet, oozing, hairless, and painful. Crusting can develop. Because the area can be extremely sensitive, clipping and cleaning may require professional handling or sedation.

Why home creams can be a problem

Thick ointments can trap moisture, and dogs often lick topical products. Human pain-relief creams, zinc compounds, essential oils, or steroid preparations may be inappropriate. Preventing further self-trauma is essential.

When should the dog be examined?

Seek care for rapidly expanding lesions, severe pain, foul odor, pus, fever, recurrent hot spots, lesions near the ear or face, or any dog that cannot stop chewing the area. Recurrence should prompt investigation for allergy, parasites, or other underlying disease.