Hot spots are unnerving because of the speed. There is nothing there in the morning. By evening there is a raw, weeping patch the size of your palm, and your dog will not stop working at it.
Two things worth knowing: the treatment is more mechanical than medical, and a dog that gets these repeatedly has a different problem from the one you are looking at.
What is actually happening?
A hot spot, acute moist dermatitis, sometimes pyotraumatic dermatitis, is self-inflicted trauma.
Something makes one area itch. The dog licks or chews it. The trauma inflames the skin, which makes it itchier and more painful, which drives more licking. Moisture is trapped, the surface breaks down, and bacteria move into the damaged skin.
That loop is why the speed is so alarming. It is not an infection spreading in the usual sense; it is a wound being actively enlarged by the dog several times a minute.
The role of bacteria in starting hot spots is not fully clear. Some cases appear to begin as folliculitis, inflammation and infection of the hair follicles, and this seems more common in heavy-coated breeds such as St Bernards and Golden Retrievers. Other cases have no significant bacterial component and respond simply to clipping, cleaning and anti-inflammatory treatment.
How to treat one properly
The treatment is unglamorous and the first step is the one everybody skips.
1. Clip the hair, generously.
Clip at least 2 to 3 cm beyond the visible edge of the lesion. This is not cosmetic. It is what lets you see the true extent, lets air reach the surface, stops surrounding fur wicking moisture back into it, and lets any topical treatment actually contact skin.
Hot spots are almost always larger than they look under fur. Clipping is when you find that out.
2. Clean off the crusts and discharge.
A mild antiseptic, chlorhexidine solution is the standard. Gently, until the surface is clean. Removing crusts and exudate matters because topical antibiotics, drying sprays and soothing preparations only work on clipped, clean skin.
3. Keep it dry.
Moisture created it. Air is the ally.
4. Stop the dog reaching it.
A cone, properly fitted and actually left on. A dog that can reach the lesion will undo everything in an hour, and half-measures here are why treatment "doesn't work".
5. Treat the pain and inflammation.
These hurt. Anti-inflammatory treatment is often what breaks the itch-lick cycle, and some cases resolve on clipping, cleaning and corticosteroid therapy alone. That is a vet's call.
What not to use: human antiseptic creams the dog will lick off, hydrogen peroxide (it damages healing tissue), and any thick ointment that seals moisture in. Wet lesions need drying, not covering.
When to see a vet rather than doing it yourself
- Spreading despite treatment, or larger than a few centimetres
- Discharging pus, or smelling
- Too painful to touch. That dog may need sedation to be clipped properly, and forcing it teaches your dog that you are the person who hurts them
- Multiple hot spots at once
- Your dog is unwell in itself, flat, off food, feverish
- Anywhere near the eye or ear canal
Why they keep coming back
A single hot spot after a wet weekend is an event. Repeat hot spots are a symptom.
If your dog has had more than one, the recommendation is a diagnostic work-up for flea allergy and other allergies, including an elimination food trial. Something is generating the itch that starts each cycle, and until it is found you are treating wounds while the cause keeps producing new ones.
The most common driver is fleas, and the giveaway is location: hot spots clustered over the tail base, rump and back of the thighs are close to diagnostic for flea allergy dermatitis, even if you have never seen a flea.
Other frequent drivers: ear disease (hot spots on the cheek and neck below an infected ear), atopic dermatitis, anal gland problems (hot spots around the rear), matted coat holding moisture, and pain in an underlying joint.
Location is evidence, note where they appear:
| Where | Suspect |
|---|---|
| Tail base, rump, back of thighs | Fleas |
| Cheek, neck, below the ear | Ear disease |
| Around the rear | Anal glands |
| Feet and legs | Atopy or contact allergy |
| Over a joint | Pain in that joint |
Prevention
Dry your dog properly. After baths, after swims, after rain. Thick-coated dogs hold water against the skin for hours and it is invisible from outside. In monsoon months this is the single most useful habit.
Keep flea control genuinely current, the whole household of dogs, not just the one with the sore.
Brush out mats, especially behind the ears, in the armpits and around the tail.
Deal with the underlying allergy if there is one. Everything else is management.
The bottom line
Clip wide, clean well, keep it dry, keep the dog off it, and get the pain under control.
Then ask the more useful question: what made the dog start licking there? A single hot spot is an accident. A pattern of them is an allergy that has not been diagnosed yet, and the location where they keep appearing is usually telling you where to look.
If hot spots arrive alongside general scratching, work the full diagnostic order, parasites, then infection, then allergy.