In the morning your dog has a small pink patch on its neck. By evening the fur is gone, the skin is red and wet, and your dog will not stop licking or scratching it. Owners are often shocked at how quickly it happens. This is a hot spot, one of the most common skin problems vets see in dogs, especially in summer.
The good news is that hot spots usually heal quickly once they are treated. The harder part is finding out what started the itching in the first place, so the sore does not come back.
What a hot spot is
Vets call a hot spot acute moist dermatitis or pyotraumatic dermatitis. In plain terms, it is a patch of skin that has been damaged by the dog’s own licking, chewing or scratching, and then taken over by bacteria.
A hot spot usually looks like:
- A round patch of red, raw skin with clear edges.
- Hair missing from the center, with matted or sticky fur around the edge.
- A wet surface that oozes clear or pale yellow fluid.
- Sometimes a bad smell, or a crust as it dries out.
Hot spots are painful, and many dogs flinch or growl if you touch them. They are often found on the neck, the side of the face below the ear, the hips, the base of the tail and the legs.
How a small itch turns into a hot spot
Every hot spot starts with something that itches or hurts. The dog licks, chews or scratches the spot to relieve it. That breaks the surface of the skin and irritates the nerve endings, which makes the area even itchier. So the dog licks more.
VCA Animal Hospitals calls this the lick-itch-lick cycle. The broken, damp skin is an ideal place for bacteria that normally live on the skin to multiply. A sore can go from a small red mark to a patch 6 inches or more across in a single night.
What starts the itching
Fleas and flea allergy
Fleas are one of the most common triggers. Some dogs are allergic to flea saliva, and a single bite can set off intense itching. A Virginia Tech veterinary dermatologist lists fleas, flea-bite allergy and environmental allergies as the main causes of hot spots, and notes that they are more common in spring and summer.
Allergies
Dogs with allergies to pollen, dust mites, grasses or certain foods often have itchy skin. Allergic dogs are more likely to get hot spots, and to get them again and again.
Ear infections
An itchy, infected ear makes a dog scratch at its head. That is why so many hot spots appear on the cheek, behind the ear or on the side of the neck.
Anal gland problems
Full or infected anal glands are uncomfortable. Dogs lick and chew around the tail to relieve the pressure, which can lead to a hot spot on the rump or the base of the tail.
Moisture trapped in the coat
Water held against the skin after swimming, a bath or a walk in the rain softens the skin and lets bacteria grow. In thick coats, the outer hair can feel dry while the undercoat next to the skin stays damp for hours. Hot, humid weather makes this worse.
Pain, boredom and stress
Dogs sometimes lick a sore joint, the way people rub a sore knee. Bored or anxious dogs may lick their legs and paws simply because those parts are right under their nose when they lie down. Both can lead to hot spots.
Matted fur and poor grooming
Mats trap moisture, dirt and heat against the skin and pull at it, which causes irritation.
Dogs most likely to get them
Any dog can get a hot spot, but the American Kennel Club notes that breeds with thick coats are more prone. These include Golden Retrievers, Labrador Retrievers, German Shepherds, Saint Bernards and Rottweilers, along with Collies and many spaniels. Water-loving dogs that swim often are at higher risk, and so are dogs with allergies.
How vets treat hot spots
Because hot spots hurt, many dogs need a mild sedative so the vet can work on them. Treatment usually includes:
- Clipping the fur around the sore, so air can reach it and it can be kept clean. The shaved area often turns out to be larger than the hot spot looked under the fur.
- Cleaning with a gentle antiseptic.
- Medicine for itch and swelling, such as a steroid or another anti-itch drug, given as a pill, a shot or a cream.
- Antibiotics if the skin infection goes deeper. Vets look for small bumps or crusts around the main sore, which can mean the infection has spread into the hair follicles.
- A cone or recovery collar, so the dog cannot keep licking or scratching.
- Treating the cause, such as flea control, ear medicine or allergy treatment.
Most hot spots start to dry and heal within a few days of treatment. Do not pick off the scab, because that slows healing.
What to do at home and what to avoid
If the spot is small and you cannot get to a vet right away, Cornell University’s College of Veterinary Medicine suggests gently cleaning it with a mild soap and keeping your dog from licking it. A clean T-shirt or a cone can help.
Avoid these common home treatments:
- Hydrogen peroxide. It damages the new cells the skin needs to heal and can sting.
- Tea tree oil and other essential oils. Tea tree oil can be toxic to dogs, and dogs tend to lick whatever is put on their skin.
- Human creams and ointments without your vet’s approval. Some contain ingredients that are unsafe if licked, and thick ointments can trap moisture.
- Covering it with a tight bandage, which keeps it damp.
See your vet soon if the hot spot is bigger than a quarter, is spreading, smells bad, bleeds, or is clearly painful, or if your dog has more than one.
How to prevent hot spots
- Use flea prevention all year, for every pet in the house.
- Dry your dog completely after swimming or a bath, down to the skin. Use a towel and a pet dryer on a cool setting for thick coats, and check the chest, neck and behind the ears.
- Brush regularly, especially double-coated breeds during shedding season, to remove loose undercoat and prevent mats.
- Treat allergies and ear infections early, before the scratching starts.
- Keep your dog busy. Daily walks, play and chew toys help reduce boredom licking.
- Check your dog’s skin during summer and after outdoor adventures, so you catch small red patches early.
If your dog gets hot spots over and over, ask your vet about allergy testing or a food trial. Repeat hot spots almost always mean there is an itch that has not been fully treated.
