Glossary

Hot spot

A fast-appearing, red, wet and painful patch of skin that a dog creates by licking or scratching, usually because of an underlying irritation.

Also called: acute moist dermatitis, pyotraumatic dermatitis, moist eczema, summer sores

A hot spot, or acute moist dermatitis, is a patch of inflamed, infected skin that can show up and spread within hours. The area looks red, raw and wet, often oozes, is painful to touch and has matted hair around it. Dogs with thick coats, such as the Golden Retriever, are prone, especially after swimming or in hot, humid weather.

The skin itself is rarely the original problem. Hot spots are usually set off by something that makes the dog lick or chew, such as fleas, allergies, an ear infection, anal sac trouble or boredom.

Because the wound can deepen quickly and hurts, a veterinarian should see it, clip the area and look for the cause. Without finding the trigger, hot spots tend to come back.

Last reviewed November 8, 2026

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Related terms

Atopic dermatitis An inherited tendency to develop itchy skin and ear disease from allergens in the environment such as pollen, dust mites and molds. Fleas Tiny blood-feeding insects that cause itching, can trigger allergic skin disease and carry tapeworm, and infest the home as well as the dog. Ear infection Inflammation of the outer ear canal, often with yeast or bacteria, causing head shaking, scratching, odor and pain.