What Exactly Is a Hot Spot?
If you've ever noticed a red, oozing, angry-looking patch on your dog's skin that seemed to appear almost overnight, you've probably encountered a hot spot. Officially called acute moist dermatitis, hot spots are one of the most common skin conditions in dogs — and one of the most frustrating for owners to deal with.
A hot spot starts when something irritates your dog's skin — a flea bite, an allergic reaction, a small scrape, or even moisture trapped under thick fur. Your dog responds by licking, scratching, or chewing at the irritated spot. This creates a cycle: the self-trauma breaks the skin, bacteria move in, the area becomes infected and itchy, so the dog scratches more, making it worse. What started as a tiny irritation can become a large, painful, weeping sore in just a few hours.
I once left for work with my Golden Retriever looking perfectly fine and came home to find a patch the size of my palm on his hip, raw and wet with matted fur stuck to it. That's how fast these things can develop.
What Hot Spots Look and Feel Like
Hot spots are pretty distinctive once you know what you're looking for:
- Red, inflamed skin that's warm to the touch
- Moist or oozing surface — they look wet and glistening
- Hair loss over and around the affected area
- Crusty or matted fur around the edges
- Foul smell — infected hot spots have a characteristic unpleasant odor
- Pain — most dogs are very sensitive about having the area touched
- Rapid growth — a small spot can double or triple in size within hours
They can appear anywhere on the body, but the most common locations are the head, neck, hips, and limbs. In dogs with thick undercoats, they often develop on the rump and flanks where moisture gets trapped.
Why Dogs Get Hot Spots
Understanding the root cause is essential for prevention, because if you only treat the hot spot without addressing what started it, it'll keep coming back.
Allergies
This is the number one underlying cause. Flea allergy dermatitis (a reaction to flea saliva — even a single flea bite can trigger it in sensitive dogs), food allergies, and environmental allergies (pollen, mold, dust) all cause itching that leads to the scratch-infect-scratch cycle.
Moisture
Dogs that swim frequently, live in humid climates, or have thick coats that stay damp are highly prone to hot spots. The moisture softens the skin and creates an ideal environment for bacteria. This is why hot spots are sometimes called "summer sores" — they peak during warm, humid months.
Poor Grooming
Matted fur traps moisture and debris against the skin. Dogs with thick double coats that aren't regularly brushed and groomed are at higher risk. Regular brushing isn't just about looking good — it's about skin health.
Ear Infections
Dogs with ear infections frequently scratch at their ears and the side of their head, creating hot spots on the cheeks and neck area. Treat the ear infection, and the hot spots often stop.
Behavioral Factors
Boredom, anxiety, and stress can cause excessive licking and chewing, which can trigger hot spots. Some dogs develop compulsive grooming habits that damage their skin.
Other Irritants
- Insect bites and stings
- Contact irritants (chemicals, rough surfaces)
- Small wounds or abrasions that the dog worries at
- Anal gland issues causing rear-end scooting and chewing
First Steps When You Find a Hot Spot
The most important thing is to stop the itch-scratch cycle. Here's what you can do before getting to the vet:
- Carefully trim the fur around the hot spot. Use blunt-tipped scissors or electric clippers to remove hair from the affected area and about an inch around it. The hot spot needs air exposure to dry out and heal. Be very gentle — the area is painful, and your dog may not appreciate this process. Having a helper hold your dog can make this much safer.
- Gently clean the area with a mild antiseptic solution recommended by your vet, or plain cool water if that's all you have. Don't use hydrogen peroxide or alcohol — these sting terribly and can damage healing tissue.
- Pat the area completely dry. Remember, moisture is the enemy here.
- Prevent further scratching. An Elizabethan collar (the cone of shame) is the most reliable way to stop your dog from reaching the hot spot. Nobody loves the cone, but it works.
When You Need the Vet
While very small, superficial hot spots sometimes respond to at-home first aid, most benefit from veterinary treatment. See your vet if:
- The hot spot is larger than a couple of inches
- It's getting worse despite your efforts
- There are multiple hot spots
- The area is deeply infected with pus or significant swelling
- Your dog is in significant pain
- It's on or near the face
- Your dog is scratching so intensely they're causing further damage
- Hot spots keep recurring
Your vet may prescribe topical or oral antibiotics to clear the infection, along with anti-inflammatory or anti-itch medications to break the scratch cycle. In severe cases, they may need to clip and clean the area under mild sedation if the dog is too painful to be handled.
Breeds Most Prone to Hot Spots
Any dog can develop a hot spot, but these breeds see them most frequently:
- Golden Retrievers
- Labrador Retrievers
- German Shepherds
- Saint Bernards
- Rottweilers
- Any breed with a thick, dense undercoat
If you own one of these breeds, proactive skin and coat care is especially important.
Long-Term Prevention Strategies
Preventing hot spots from coming back requires addressing the underlying cause and maintaining good skin health:
Stay on Top of Flea Prevention
Year-round flea prevention is non-negotiable, especially for allergy-prone dogs. Even one flea bite can set off a cascade of scratching and hot spot development in a flea-allergic dog. Talk to your vet about the most effective flea prevention for your area.
Regular Grooming
Brush your dog regularly, especially during shedding seasons. For breeds with thick undercoats, consider professional grooming to remove the dense undercoat that traps moisture. Keep the coat clean and dry.
Dry Your Dog Thoroughly
After swimming, baths, or getting caught in the rain, dry your dog's coat thoroughly — especially in the areas where hot spots tend to develop. A high-velocity pet dryer can be a worthwhile investment for thick-coated breeds.
Address Allergies
If allergies are the root cause, work with your vet on a management plan. This might include elimination diets for food allergies, environmental allergy testing, immunotherapy, or medications to control itching.
Keep Your Dog Mentally Stimulated
For dogs that lick and chew out of boredom, increase exercise, provide puzzle toys, and ensure they're getting enough mental stimulation. A tired, engaged dog is less likely to develop destructive grooming habits.
Regular Skin Checks
Get into the habit of running your hands through your dog's coat daily, especially during summer months. Catching a small irritation before it becomes a full-blown hot spot makes management so much easier.
The Healing Process
With proper treatment, most hot spots improve significantly within 3-7 days and fully heal within 1-2 weeks. You'll see the area dry out, the redness decrease, and eventually new fur growing back. Complete the full course of any prescribed medications even if it looks better — stopping antibiotics early can lead to resistant infections.
During healing, keep the area clean and dry, prevent your dog from licking or scratching it, and watch for signs that the infection is spreading or not responding to treatment. Follow up with your vet if things aren't improving as expected.