Pet Allergies: Symptoms, Causes & When to See a Vet

Understanding Pet Allergies

Allergies are one of the most common causes of skin and ear problems in dogs and cats. These reactions occur when the immune system overreacts to a normally harmless substance, causing itching, inflammation, or digestive upset.

Many pet parents first search for “dog allergy symptoms” or “cat allergy symptoms” because the early signs can be subtle. Recognizing these symptoms early can prevent infection and keep pets comfortable.

Types of Pet Allergies

1. Environmental (Seasonal) Allergies

Environmental allergies—also called atopic dermatitis—occur when pets react to substances like pollen, dust mites, or mold.

Common triggers: 

• Pollen from grasses, trees, and weeds

• Mold spores

• Dust and dust mites 

• Grass contact 

• Smoke or fragrances

These often begin seasonally but may progress to year-round irritation.

2. Food Allergies

Food allergies happen when a pet’s immune system reacts to a specific ingredient in their diet.

Common triggers: 

• Chicken, beef, dairy, eggs, or fish 

• Wheat, soy, corn (less common) 

• Artificial preservatives

Food allergies can cause chronic itching, GI issues, and repeated ear infections.

3. Flea Allergy Dermatitis (FAD)

Just one flea bite can trigger an intense allergic reaction.

• Typical signs: 

• Intense itching

• Hair loss near the tail base

• Red bumps or scabs 

• Secondary infections

Year-round flea prevention is essential for pets with FAD.

4. Contact Allergies

Contact allergies occur when the skin reacts to something your pet touches.

Possible triggers: 

• Shampoos or detergents 

• Cleaning agents

• Fabrics or rugs 

• Plastic bowls

Irritation usually appears on the belly, feet, or face.

Dog Allergy Symptoms

Dogs typically show allergies through their skin.

Common symptoms include:

• Itching (paws, belly, ears) 

• Red or inflamed skin

• Licking or chewing feet 

• Recurrent ear infections 

• Rashes, bumps, or hair loss 

• Sneezing or mild coughing

If you’ve ever asked “Why is my dog so itchy?” — allergies are a leading cause.

Cat Allergy Symptoms

Cats often display more subtle signs of allergies.

Common symptoms include:

• Overgrooming or hair pulling 

• Small scabs (miliary dermatitis) 

• Itching around the face or neck

• Recurrent ear infections

• Watery eyes or sneezing

• Vomiting or diarrhea (food allergy related)

• Swollen lips (eosinophilic granuloma complex)

Overgrooming is one of the most common signs of allergies in cats.

General Allergy Symptoms in Pets

Pets with allergies may show one or multiple symptoms:

• Persistent itching or licking 

• Red, flaky, or irritated skin 

• Hair loss or bald patches 

• Ear infections or head shaking 

• Sneezing or watery eyes 

• GI issues such as vomiting or diarrhea

• Early intervention helps prevent more serious skin or ear infections.

Diagnosing Pet Allergies

Veterinarians diagnose allergies using:

• Physical examination

• Medical and environmental history

• Skin tests & infection checks 

• Allergy blood or intradermal testing (environmental)

• Elimination diet (food allergies — most accurate)

  
  

A correct diagnosis ensures the most effective long-term treatment.

Managing and Treating Pet Allergies

Effective treatment options include:

• Allergen avoidance 

• Antihistamines or corticosteroids

• Fatty acid supplements • Apoquel® or Cytopoint® for itching

• Immunotherapy (allergy shots/drops)

• Medicated shampoos

• Year-round flea control 

• Hypoallergenic or limited-ingredient diets

Your veterinarian will build a treatment plan based on your pet’s specific allergy type.

Read more here about how EVS uses Cytopoint to alleviate allergies.

Preventive Care & At-Home Tips

• Vacuum and dust the home regularly

• Wash bedding and toys frequently

• Use an air purifier during allergy season

• Wipe paws after outdoor play

• Bathe with gentle, vet-approved shampoos

• Keep pets on consistent flea prevention

Consistency is key for long-term allergy management.

Pet Allergies FAQs

What are the first signs of allergies in dogs?

Itching, licking paws, red skin, and recurring ear infections.

How do I know if my cat has allergies?

Common signs include overgrooming, scabs, ear issues, and itching around the face.

Can food allergies cause ear infections?

Yes. Chronic or recurring ear infections often point to food allergies.

Why is my dog so itchy but doesn’t have fleas?

Environmental allergies, food sensitivities, and yeast/bacterial skin infections are common reasons.

When should I take my pet to the vet?

If you suspect your pet may be experiencing allergies—or if itching, skin redness, or ear issues persist—it's important to consult with a veterinarian. Allergies can worsen over time and often require proper diagnosis and treatment to keep your pet comfortable and healthy.

If your pet is showing signs of allergies, EVS Pet Urgent Care is ready to help. Our experienced veterinary team can diagnose and treat allergic conditions quickly and compassionately.

EVS can help — find a location near you.