Why is My Dog Itching? The Complete Guide to Dog Allergies

The sound is unmistakable: Slurp, slurp, chew, chew. You wake up in the middle of the night to the sound of your dog gnawing on their foot. Their paws are red, their belly is rashy, and they seem miserable.

Itchiness (pruritus) is one of the top reasons owners visit the vet. But solving it can be a detective game. Is it the chicken in their food? The pollen in the grass? Or just fleas?

In this guide, we will break down the “Itch Cycle” and explain why changing dog food usually isn’t the answer (hint: it’s rarely the food).

The Big Three Causes of Itch

1. Fleas: The #1 culprit. Even if you don’t see them. One flea bite can trigger a massive reaction in a sensitive dog (Flea Allergy Dermatitis).
2. Environmental Allergies (Atopy): Pollen, dust mites, mold, grass. This is the canine version of Hay Fever, but instead of sneezing, they itch.
3. Food Allergies: Surprisingly rare (only ~10% of allergy cases).

Atopy: The “Hay Fever” of Dogs

If your dog itches mostly in the Spring or Fall, it’s likely environmental. Symptoms:

• Licking paws (yeast infection from saliva makes them turn rust-colored).
• Rubbing face on carpet.
• Recurring ear infections.
• Hot spots.

Treatment: You can’t cure it, but you can manage it.

• Cytopoint: An injection that neutralizes the “itch signal” in the body. Safe and lasts 4-8 weeks.
• Apoquel: A daily pill that blocks itch receptors.
• Bathing: Weekly baths with medicated shampoo wash off the pollen.
• Wiping Paws: Wipe their feet with baby wipes after every walk to remove grass allergens.

Food Allergies: The Myth vs. Reality

Marketing has convinced us that “grains” are the enemy. Fact: Most food-allergic dogs are allergic to the protein (Chicken, Beef, Dairy), not the grain (Corn, Wheat).

Symptoms:

• Itching usually affects the rear end (anus) and ears.
• GI upset (vomiting/diarrhea).
• Non-seasonal (itches year-round).

The Only Test: The Elimination Diet. Blood tests for food allergies are notoriously inaccurate. The gold standard is an Elimination Diet Trial.

1. Feed a prescription Hydrolyzed Protein diet (where the protein is broken down so small the body doesn’t recognize it).
2. Feed NOTHING else for 8 weeks. No flavored treats, no toothpaste, no table scraps.
3. If the itch stops, reintroduce chicken. If the itch returns, you have your diagnosis.

When to See a Vet

Don’t wait until the skin is raw. Constant scratching breaks the skin barrier, leading to secondary Staph (bacterial) or Yeast infections. If your dog smells like corn chips (yeast) or has scabs (bacteria), they need antibiotics/antifungals plus itch relief.

Summary

• Step 1: Perfect flea control (Bravecto/Simparica).
• Step 2: Consult a vet for itch relief (Cytopoint/Apoquel).
• Step 3: If that fails, consider a diet trial.

Stop the itch, stop the infection, and let your dog sleep through the night again.