Mild weather year-round sounds like good news for dogs, but it actually means the skin threats that plague other regions only in summer never really take a break here. Because San Diego rarely sees a hard freeze, fleas, pollen, and the humidity that traps moisture against a dog's coat can all be active in almost any month. That's why thinking about hot spots and itchy skin on a seasonal calendar, rather than just a "summer problem," helps local pet owners catch issues before they spiral.
The Pet Hospital of Tierrasanta is a veterinary clinic in San Diego that treats hot spots, allergic skin disease, and secondary infections in dogs throughout the year, not just during peak flea season. Below, we'll walk through what tends to flare up and when, so you know what to watch for no matter the month on the calendar.
Why Coastal Weather Keeps Dog Skin Vulnerable All Year
Hot spots, medically called acute moist dermatitis, are fast-developing, red, oozing patches of irritated skin. They commonly show up on the neck, hips, rump, or behind the ears, and they can spread within hours once a dog starts licking or scratching at the area. The marine layer and humidity common along the coast keep moisture sitting against a dog's fur longer than it would in a drier inland climate, which creates exactly the damp environment bacteria need to take hold.
Thick-coated breeds, including golden retrievers, German shepherds, and Labrador retrievers, face a higher risk because their undercoat holds onto dampness after a swim, a bath, or a foggy morning walk. Add fleas, which survive comfortably in Southern California's mild winters, and you have a recipe for irritation that doesn't wait for a particular season to appear.
Winter and Early Spring: Flea Activity Rarely Pauses
Unlike colder climates where frost knocks back the flea population, San Diego's winters stay warm enough that fleas can continue reproducing in yards, under decks, and in shaded garden beds. For dogs with flea allergy dermatitis, it only takes a single bite to set off an intense, body-wide itching reaction. This is the single most common allergy trigger we see, and it's also the most preventable, since consistent, year-round flea control stops the cycle before it starts.
Owners sometimes assume cooler months mean they can skip a dose of flea prevention. In this climate, that gap is exactly when flea populations rebound and allergic dogs start scratching again.
Spring Bloom: Pollen and Grass Allergies Peak
Spring in the region brings heavier pollen counts from grasses, trees, and weeds, and that's when environmental allergies tend to flare hardest. Watch for persistent scratching, paw licking, red or watery eyes, and ear scratching during these months. Dogs with environmental sensitivities often show a second, smaller flare in the fall as different plants release pollen, so the pattern tends to be two peaks rather than one long stretch.
Food allergies, by contrast, don't follow a season at all. They show up anytime and are usually tied to proteins like beef, chicken, or dairy, along with wheat. They're less common than flea or environmental allergies, but they still deserve a conversation with your vet if the itching doesn't fit a seasonal pattern.
Summer: Beach Days and Backyard Play Raise Hot Spot Risk
Warmer months bring more swimming, more time outdoors, and more opportunities for fur to stay damp for hours after a trip to the beach or a backyard sprinkler session. That dampness, combined with insect bites, stings, or a dog scratching at an already irritated patch of skin, is what tips a minor irritation into a full hot spot. Because these lesions can double in size within a day, catching one early matters more than almost anything else you can do.
If you notice a small, moist, red patch, clip the fur around it, clean gently with a mild antiseptic made for dogs, keep the area dry, and use an e-collar to stop further licking. Skip human products like hydrogen peroxide or Neosporin unless your veterinarian specifically recommends them, since these can slow healing or irritate the skin further. A hot spot larger than a quarter, one that's spreading, or one that hasn't improved within 24 to 48 hours needs a veterinary exam, not more home treatment.
Fall: Dry Winds and Lingering Secondary Infections
Santa Ana wind events bring low humidity and dust that can dry out and crack already irritated skin, opening the door for secondary infections in dogs who've been dealing with allergies all summer. Bacterial infections (pyoderma) tend to look like red bumps with crusting, hair loss, and a noticeable odor, and they're often caused by Staphylococcus bacteria that take advantage of a broken skin barrier. Yeast infections (Malassezia) show up differently: greasy or flaky patches, dark discoloration, a musty smell, and intense itching, usually concentrated in skin folds, ears, and paws.
Both conditions can look alike to an untrained eye but require different treatments entirely, which is why a skin cytology (a quick microscopic look at a skin or ear sample) is usually the fastest way to confirm what's actually going on and get the right medication started.
Knowing When Home Care Isn't Enough
Mild, early-stage hot spots and occasional seasonal itchiness often respond well to home care and a bit of patience. But a few signs mean it's time to bring your dog in rather than wait it out: symptoms lasting more than 48 hours, visible pain, spreading or oozing skin, hair loss, or a dog who can't settle down to sleep because of the itch. Veterinarians at The Pet Hospital of Tierrasanta can run a full skin evaluation, identify whether fleas, environment, food, or infection is driving the problem, and build a treatment plan around your dog's specific triggers and the time of year they tend to flare.
Frequently Asked Questions
Do dogs in San Diego need flea prevention in the winter?
Yes. Because temperatures rarely drop low enough to kill off fleas locally, year-round flea prevention is the best way to protect allergic dogs from sudden itching flare-ups.
Why does my dog get hot spots after swimming?
Damp fur left against the skin after a swim creates the warm, moist environment bacteria need to multiply, which is exactly how a small irritation turns into a fast-spreading hot spot.
Can dry winds make my dog's allergies worse?
Dust and low humidity during wind events can crack already irritated skin, making it easier for secondary bacterial or yeast infections to take hold on top of an existing allergy.
How can I tell if my dog has a bacterial or yeast skin infection?
Red bumps with crusting and odor usually point to a bacterial infection, while greasy, flaky skin with a musty smell suggests yeast, though a veterinary skin test is the only reliable way to know for sure.
Is it normal for my dog's allergies to flare twice a year?
Yes, many dogs with environmental allergies show one peak in spring and a second, smaller one in fall as different plants and grasses release pollen.
If your dog has been dealing with itchy skin, a stubborn hot spot, or recurring ear and paw issues no matter the season, reach out to The Pet Hospital of Tierrasanta to schedule a skin exam. Our team offers diagnostics and imaging, parasite prevention, and wellness exams to help keep your dog comfortable through every season San Diego throws at them.
Book an Appointment or call us at (858) 569-7777.