Hot Spots and Acute Moist Dermatitis

Hot spots (acute moist dermatitis) are one of the most common skin conditions in dogs, characterized by areas of intense inflammation, infection, and moisture on the skin. They appear suddenly — often seemingly overnight — and can grow rapidly from a small area to a large, painful lesion within hours. Hot spots are especially common in dogs with thick coats, during warm humid months, and in breeds with dense undercoats.

## What Causes Hot Spots

Hot spots begin when a dog repeatedly licks, scratches, or chews at an area of skin due to an underlying itch or irritation. The self-trauma breaks the skin surface, introducing bacteria that quickly colonize the warm, moist environment. The resulting infection causes more itching, which leads to more scratching, creating a vicious cycle of self-trauma and infection.

**Common underlying triggers include:** Flea allergy dermatitis (most common trigger), environmental allergies (atopic dermatitis), food allergies, ear infections (leading to scratching behind the ears), anal gland issues (leading to chewing at the tail base), insect bites, contact irritants, matted or tangled fur trapping moisture, swimming or bathing without thorough drying, minor wounds or abrasions, boredom or behavioral licking, and arthritis pain (licking at sore joints).

## Breeds at Higher Risk

Golden Retrievers, Labrador Retrievers, German Shepherds, Saint Bernards, Rottweilers, and any breed with thick, dense coats are predisposed. The dense undercoat traps moisture against the skin, creating an ideal environment for bacterial growth.

## What Hot Spots Look Like

Hot spots typically appear as red, moist, oozing patches of skin. The area is usually hairless or has matted fur stuck to it. The lesion is clearly defined with distinct borders. There may be pus or serum oozing from the surface. The surrounding fur is often wet or matted. The skin is warm to the touch. The area is extremely painful — dogs may cry or snap when it is touched. Hot spots are most commonly found on the head, neck, hip, and limb areas.

## Home First Aid (Mild Cases Only)

For small, superficial hot spots (smaller than a quarter) in an otherwise comfortable pet, carefully clip the fur around and over the hot spot to allow air exposure, gently clean the area with dilute chlorhexidine solution or mild antiseptic wash, pat dry and apply a thin layer of veterinary-recommended topical treatment, prevent licking with an Elizabethan collar (cone), and monitor for improvement over 24-48 hours.

**Do NOT apply hydrogen peroxide (irritating), alcohol (painful), or cortisone cream (pets will lick and ingest it).** Do NOT bandage the area — hot spots need air exposure to heal.

## When to See a Vet

Seek veterinary care if the hot spot is large (bigger than a quarter or your palm), spreading rapidly, or deep. Also if the pet is in significant pain or distress, there are multiple hot spots, the hot spot recurs frequently, or it is near the eye, ear, or other sensitive area. Your veterinarian may prescribe oral antibiotics for deep or extensive infections, prescription topical medications, pain management, anti-itch medications to break the scratch cycle, and diagnostics for the underlying cause.

## Treatment and Healing

With proper treatment, hot spots typically show significant improvement within 3-7 days. Complete healing with hair regrowth takes 2-4 weeks. The most important aspect of treatment is identifying and addressing the underlying trigger to prevent recurrence.

## Prevention

Maintain consistent flea prevention year-round. Keep dogs well-groomed with regular brushing to prevent mats. Dry dogs thoroughly after swimming or bathing, especially the undercoat. Address underlying allergies with your veterinarian. Keep ears clean and dry. Provide adequate exercise and mental stimulation to prevent boredom-related licking.