Hot Spots in Dogs: How to Treat and Prevent Acute Moist Dermatitis

What Is a Hot Spot?

Hot spots (acute moist dermatitis) are rapidly developing areas of inflamed, infected skin. They appear suddenly as a red, moist, oozing area that the dog aggressively licks, chews, or scratches — worsening the inflammation and infection in a vicious cycle. Hot spots can go from nothing to a quarter-sized weeping wound in hours. They're most common in thick-coated breeds and tend to appear in warm, humid weather.

Common Triggers

Hot spots typically start with something that causes the dog to scratch or chew at an area: flea bites (flea allergy dermatitis is a common trigger), moisture trapped in the coat from swimming or bathing, environmental allergies causing skin irritation, ear infections that prompt scratching, or contact irritants. Identifying and addressing the trigger is as important as treating the hot spot itself.

Home Management for Small Hot Spots

For small, early hot spots: gently clip the fur around the area to allow air exposure and product contact. Clean with mild antiseptic soap or chlorhexidine solution. Apply a veterinarian-approved topical spray. Prevent licking with an e-collar. Monitor closely — a hot spot that isn't improving within 24-48 hours needs veterinary care.

When Veterinary Care Is Necessary

See your vet for hot spots that are larger than a quarter size, spreading rapidly, near the face or ears, have swelling beyond the lesion, or haven't improved with home treatment. Vets typically clip, clean thoroughly, and prescribe topical and oral antibiotics plus corticosteroids to break the itch-scratch cycle.

Prevention

Key prevention: strict year-round flea prevention (a single flea bite can trigger a hot spot in a sensitive dog), thorough drying after swimming or bathing, regular brushing to reduce matting that traps moisture, and management of underlying allergies or other skin conditions that cause initial scratching.