After a humid afternoon at the lake, Marcus noticed a wet, angry patch beneath his golden retriever Cooper's collar — raw skin, matted fur, and a smell that appeared overnight. Cooper had been scratching his neck for two days, but Marcus assumed it was just summer itchiness. By evening the spot had doubled in size, oozing and hot to the touch.

Hot spots — acute moist dermatitis — are painful, rapidly spreading skin infections that thrive where moisture, heat, and bacteria meet broken skin. The neck is a prime target in summer because collars trap sweat, lake water, and saliva from licking. Early treatment stops a small red patch from becoming a shaved, antibiotic-requiring wound within hours.

Key points at a glance

  • Hot spots are bacterial skin infections that spread fast; neck and collar areas are common in warm, humid weather.
  • Moisture from swimming, drooling, or a wet collar plus scratching creates the perfect environment.
  • Early signs: small red moist patch, matted fur, intense licking, and a sour odor.
  • First aid: trim surrounding fur, clean gently, keep dry, and prevent licking — then call your vet promptly.
  • Untreated hot spots worsen quickly; underlying allergies or ear infections often trigger repeat episodes.

Why the neck in summer?

Several factors converge on the neck and collar line:

Trapped moisture — Wet fur under a collar after swimming or heavy drooling keeps skin damp for hours. Bacteria multiply in that warm, dark space.

Friction and heat — Collars rub already irritated skin. Thick-coated breeds hold heat against the neck.

Self-trauma — Itching from allergies, flea bites, or ear infections makes dogs lick and scratch the neck relentlessly. One broken hair follicle is enough to start a hot spot.

Breed tendency — Golden retrievers, Labradors, and other thick-coated dogs are frequent victims, though any breed can develop them.

Cooper's lake swim plus a damp collar left on all afternoon is a textbook setup.

How to treat hot spots early

Speed matters. Hot spots can grow from a coin-sized lesion to a palm-sized wound in a single day.

Step 1: Stop the licking. An Elizabethan collar or inflatable recovery collar prevents further damage immediately.

Step 2: Expose the area. Carefully clip fur around the spot — only if your dog tolerates it and the lesion is superficial. Matted fur holds moisture and bacteria.

Step 3: Clean gently. Use a vet-recommended antiseptic wash or saline solution. Avoid harsh products like hydrogen peroxide, which delay healing.

Step 4: Keep it dry and airy. Remove the collar until healed. Let the area breathe.

Step 5: Call your vet. Even early hot spots often need topical or oral antibiotics, plus anti-inflammatory medication for pain. Your vet will also check for underlying triggers — ear infections, fleas, or food allergies — that caused the initial itch.

Do not apply over-the-counter steroid creams without guidance; they can mask infection and worsen bacterial growth. Seek same-day care if the spot is larger than a quarter, spreading, or if your dog is lethargic. Dry thoroughly after swimming, remove damp collars indoors, and stay current on flea prevention to reduce repeat episodes.

The bottom line

Cooper's neck hot spot after a summer swim is a common, treatable emergency that gets worse without fast action. Moisture trapped under a collar plus scratching creates an infection that spreads within hours. Trim, clean, dry, prevent licking, and see your vet early — that sequence turns a scary raw patch into a manageable problem instead of a shaved, medicated recovery that lasts weeks.

This article is for general information only and is not a substitute for advice from your veterinarian.