Hot Spots on Dogs: Causes, Treatment and Prevention

A hot spot is the skin equivalent of a house fire: small at ignition, frighteningly fast to spread, and mostly fuelled by the occupant. The medical name, acute moist dermatitis, describes it well: a red, wet, inflamed patch of skin that the dog keeps licking, chewing and scratching, which damages the skin further, which makes it itch and hurt more, which makes the dog lick harder.

The single most important fact about hot spots is their speed. A patch the size of a two-pound coin at breakfast can be the size of your palm by dinner. That is why the rule with hot spots is simple: act today, not tomorrow.

What starts a hot spot

Every hot spot begins with an itch or an irritation. The common triggers:

The classic victims are dense-coated, water-loving breeds: Golden Retrievers, Labradors, German Shepherds and Bernese Mountain Dogs, especially in warm, humid weather.

Recognising one early

Part the fur and look. An early hot spot is a localised red patch, often with the fur over it looking darker or clumped from saliva. As it develops it becomes moist, glossy, sometimes oozing, and the surrounding fur mats with discharge. It is usually intensely itchy or painful, which is why the dog cannot leave it alone.

Run your fingers through the coat during brushing, especially behind the ears, under the collar, on the cheeks, and around the tail base and hips. These are the hotspot postcodes.

Treating a small one at home

For a small, fresh hot spot (smaller than a coin, no smell, no heavy oozing, dog otherwise well), this is the standard approach:

1. 1Clip the fur around and over the lesion with blunt-nosed scissors or clippers, going a couple of centimetres beyond the red edge. Trapped fur keeps it wet.
2. 2Clean gently with a vet-approved antiseptic such as diluted chlorhexidine, then pat dry. Do not use hydrogen peroxide or alcohol, which damage healing skin.
3. 3Stop the licking. A recovery collar or soft cone is not optional; it is the treatment. Every lick resets the clock.
4. 4Keep it dry. No swimming, no baths, and dry the coat properly if the dog gets wet.
5. 5Check it twice a day. It should look drier and calmer within 24 hours. If it does not, it needs a vet.

Owners apologise for the cone. Vets prescribe it. The kindest thing you can do for a hot spot is make it unreachable.

When the vet is the right answer

Most hot spots beyond the earliest stage need professional treatment, which typically means clipping and cleaning under sedation if the area is painful, plus anti-itch and antibiotic medication. Book promptly if you see:

• Oozing, pus or a noticeable smell
• A lesion larger than your palm, or visibly growing
• Pain: flinching, snapping or guarding the area
• A hot spot on the face or near the eyes
• Fever, lethargy or a dog that seems unwell
• No improvement after 24 hours of home care

Not sure how bad it is?

Because the home-care window is narrow and the spread is fast, a quick structured check helps. The tool below weighs size, oozing, smell, pain and location, and tells you which side of the vet line you are on.

What does a hot spot look like, day by day?

A hot spot, properly called acute moist dermatitis or pyotraumatic dermatitis, moves faster than almost any other skin problem in dogs. That speed is the defining feature, and it is why owners so often say it appeared overnight.

The matting over the top is the trap. Fur glued down by discharge can hide a lesion three times larger than it looks. If you part the coat and find the patch keeps going, that is your cue to call the vet rather than continue at home.

A hot spot is not the problem. It is the dog telling you, loudly, that something made them itch.

Which dogs get hot spots most?

Thick-coated and double-coated breeds top every list, because a dense undercoat holds water against the skin after swimming, rain or bathing. The Golden Retriever, Labrador Retriever, German Shepherd and Saint Bernard appear often in veterinary texts. Dogs with atopic dermatitis or food allergies are also over-represented, as are dogs with ear infections, which explains why so many hot spots appear on the cheek just below the ear.

Season matters too. Warm, humid weather, flea season and swimming season overlap neatly in late summer, and many practices see a seasonal rise. Dogs that are bored, anxious or under-exercised may lick more, and that licking alone can be enough to start the cycle.

Your home-care plan for a small, early spot

Only treat at home if the patch is smaller than a large coin, your dog lets you handle it calmly, and there is no fever, lethargy or deep wound. Otherwise go straight to the vet.

1. 1Ask a helper to steady your dog and offer treats. Never risk a bite on a sore, painful area.
2. 2Clip the hair around the lesion with blunt-ended scissors or clippers, so air reaches the skin. Leave a margin of clear skin around the edge.
3. 3Clean gently with lukewarm water or a dilute antiseptic your vet has recommended, such as chlorhexidine. Pat dry with clean gauze.
4. 4Do not use human creams, tea tree oil, hydrogen peroxide or alcohol. They sting, delay healing and some are toxic if licked.
5. 5Stop the licking. A soft cone or a fitted recovery suit is usually more effective than any spray.
6. 6Check twice daily. The patch should look drier and smaller within 24 to 48 hours. If it is larger or wetter, book an appointment.

The prevention checklist

• Towel and blow-dry thick coats on a cool setting after every swim or bath
• Brush out the undercoat weekly, daily during the moult, so mats never form
• Keep year-round flea prevention up to date for every pet in the home
• Treat ear infections promptly, because ear itch often leads to cheek hot spots
• Note the location of each hot spot; recurring spots in the same place suggest a local cause
• Talk to your vet about allergy testing if your dog has more than two or three a year
• Give enough exercise and enrichment to reduce boredom licking

Our guide to how often to bathe a dog covers drying technique in detail, and the ideal weight tool helps you check that skin folds in a heavier dog are not adding to the problem.

The verdict, by situation

First hot spot, small, dog otherwise well: clip, clean, cone and watch for 48 hours.

Large, spreading or painful: vet today. Most need clipping under sedation, plus medication to settle inflammation and sometimes antibiotics.

Recurring hot spots: the spot is a symptom. Ask your vet to look for fleas, allergies, ear disease or orthopaedic pain causing a dog to lick one area.

Swimmers and thick coats: the towel and the dryer are your best prevention, every single time.

Prevention: dry coats and flea control

Two habits prevent most hot spots. First, flea control kept rigorously up to date, because one flea bite is the most common ignition of all. Second, drying: after every swim, bath or wet walk, dry the coat properly down to the skin, especially in dense or double-coated breeds. A towel is not enough for a Golden Retriever in October; use a dryer on a cool setting.

Add regular brushing to catch mats and seeds early, and give bored dogs more to do, and you have covered the main triggers. Hot spots are dramatic, but they are also one of the most preventable skin problems a dog can have.

Hot spot myths, checked

Treat every hot spot as a clue. The patch heals in a fortnight; the cause, if you find it, stays solved for years.