If your dog develops red patches, inflamed skin, or itchy rashes every summer, you are NOT alone. Seasonal rashes are extremely common—especially when temperatures rise and humidity increases.

But why does it happen only in summer?
What triggers the flare-ups?
And how do you prevent it from returning every year?

Let’s break down the most common causes, how to recognize each one, and what you can do about it.

1️⃣ Seasonal Allergies (Environmental Allergens)

The #1 cause of summer rashes

Just like people develop hay fever, dogs develop summer dermatitis—a reaction to:

• Grass pollen
• Weed pollen
• Mold spores
• Dust and outdoor allergens

Common signs:

• Red rash on belly, armpits, or paws
• Constant licking or scratching
• Hair loss in itchy areas
• Paw chewing

Why summer makes it worse:

Allergen counts peak → dogs spend more time outdoors → more exposure.

2️⃣ Heat Rash (Hot Weather Dermatitis)

Rashes caused by trapped moisture + heat

Dogs can get a rash similar to human heat rash when sweat glands get clogged—especially in thick-coated breeds.

Common areas:

• Belly
• Groin
• Armpits
• Neck folds

Triggers:

• High humidity
• Poor air circulation under dense fur
• Staying wet after swimming

3️⃣ Flea Allergy Dermatitis (FAD)

Even ONE flea bite can trigger a severe summer rash

Fleas thrive in warm weather. Some dogs are allergic to flea saliva, causing a huge rash response.

Signs:

• Red bumps on lower back or tail base
• Intense itching
• Scabs and hair loss

If your dog gets a rash every summer → flea allergy is a major suspect.

4️⃣ Contact Irritation

Skin reaction from touching summer plants or surfaces

Summer = more outdoor contact with:
• Grass blades
• Fertilized lawns
• Chemicals
• Weeds that irritate the skin

Dogs with short coats or shaved fur are even more vulnerable.

5️⃣ Yeast Overgrowth (from heat + moisture)

Summer humidity increases yeast growth on the skin

Yeast thrives in warm, damp areas of the dog’s body.

Signs:

• Reddish-brown rash
• Sticky or greasy skin
• Musty odor
• Darkened skin over time

Often affects belly, armpits, groin, and paws.

6️⃣ “Hot Spots” (Acute Moist Dermatitis)

Rapid-forming summer rashes that spread quickly

Hot spots commonly develop in summer due to heat, humidity, insect bites, or allergies.

Signs:

• Red, raw patches
• Moist, oozing skin
• Painful to touch
• Spreads fast if untreated

📌 When Should You See a Vet?

Seek veterinary care if you notice:
❗ Rash spreading or worsening
❗ Constant scratching or chewing
❗ Open sores or bleeding spots
❗ Foul smell (possible yeast)
❗ Lethargy or decreased appetite
❗ Repeated rash every summer

Long-term management often requires allergy treatment, flea control, and better skin protection.

📌 How to Prevent Summer Rashes

✔ Keep your dog on year-round flea prevention
✔ Bathe weekly with a gentle, anti-itch shampoo
✔ Use hypoallergenic wipes after outdoor play
✔ Keep fur trimmed (but avoid shaving double-coated breeds)
✔ Add omega-3 supplements for skin barrier support
✔ Reduce exposure to grass and weeds when pollen is high

Consistent management reduces flare-ups dramatically.