Allergies in Cats & Dogs: What Every Pet Owner Should Know

Allergies are a common reason pets visit the veterinarian, affecting both dogs and cats in a variety of ways. Just like people, pets can develop sensitivities to substances in their environment, food, or even parasites. Understanding the signs of allergies and knowing how they are diagnosed and managed can help pet owners keep their animals comfortable and healthy.

What Causes Allergies in Pets?

Allergies occur when the immune system overreacts to a typically harmless substance (allergen). In dogs and cats, the most common types of allergies include:

• Environmental allergies (atopy): Triggered by pollen, dust mites, mold, or grasses

• Flea allergy dermatitis: A reaction to flea saliva

• Food allergies: Usually related to specific proteins like chicken, beef, or dairy

While dogs are more commonly affected by environmental and flea allergies, cats can also develop these, along with food sensitivities.

Common Symptoms

The signs of allergies in pets can vary depending on the cause, but many symptoms overlap.

In dogs:

• Persistent itching (especially paws, ears, belly, or face)

• Red, inflamed skin

• Chronic ear infections

• Hair loss or recurrent skin infections

• Scooting or licking the rear

In cats:

• Excessive grooming or hair loss (often leading to bald patches)

• Scabs or small crusty lesions (sometimes called “miliary dermatitis”)

• Itching, especially around the head and neck

• Vomiting or diarrhea (more common with food allergies)

Unlike humans, pets rarely show classic “hay fever” symptoms like sneezing or watery eyes. Instead, skin and ear issues are the most common indicators.

How Are Pet Allergies Diagnosed?

Diagnosing allergies in pets can take time and often involves ruling out other conditions first. Your veterinarian will typically start with a thorough history and physical exam, followed by targeted testing.

Common diagnostic steps include:

• Flea control trial: Because flea allergy is so common, ensuring strict flea prevention is often the first step

• Skin tests: Skin scrapings or cytology may be performed to check for infections or parasites

• Food elimination trial: Feeding a prescription or novel protein diet for 8–12 weeks to identify food allergies

• Allergy testing: Blood tests or intradermal skin testing may help identify environmental allergens, especially if immunotherapy is being considered

It’s important to note that there is no single “quick test” for all allergies. A step-by-step approach helps ensure accurate diagnosis and effective treatment.

Treatment Options

Managing allergies in pets usually involves a combination of therapies tailored to the individual animal and the severity of their symptoms.

1. Allergen Avoidance 

When possible, reducing exposure to known allergens can help. This might include frequent cleaning, air filtration, or limiting outdoor time during high pollen seasons.

2. Flea Prevention 

Year-round flea control is essential, especially for pets with flea allergy dermatitis. Even a single bite can trigger intense itching.

3. Medications for Itch and Inflammation 

Veterinarians may prescribe medications to control itching and inflammation, including:

• Antihistamines: Mild relief for some pets, often used in combination with other therapies

• Corticosteroids: Effective for short-term control of severe itching, but typically avoided long-term due to potential side effects

• Cytopoint: A monoclonal antibody injection for dogs that targets itch-specific pathways (IL-31). It can provide relief for several weeks with minimal systemic side effects

• JAK inhibitors (e.g., Apoquel): Oral medications that block itch and inflammation signals at the cellular level. They work quickly and are commonly used for moderate to severe allergies in dogs

• Antibiotics or antifungals: Used when secondary skin or ear infections are present

  
  

4. Immunotherapy (Allergy Shots or Oral Drops) 

For environmental allergies, immunotherapy can help “train” the immune system to be less reactive. This is the only treatment aimed at modifying the underlying allergic response and can significantly reduce symptoms over time.

5. Special Diets 

For pets with food allergies, a strict hypoallergenic or limited-ingredient diet is key. Once the offending ingredient is identified, it must be avoided long-term.

6. Topical Therapies 

Medicated shampoos, wipes, and sprays can help soothe irritated skin, treat infections, and remove allergens from the coat.

When to See a Veterinarian

If your pet is showing signs of persistent itching, skin irritation, ear infections, or gastrointestinal issues, it’s important to seek veterinary care. Early intervention can prevent secondary infections and improve your pet’s quality of life.

Final Thoughts

Allergies in dogs and cats can be frustrating for both pets and their owners, but they are manageable with the right approach. By recognizing the symptoms early, working closely with your veterinarian, and following a tailored treatment plan—including newer targeted therapies like Cytopoint and JAK inhibitors—you can help your pet live a more comfortable, itch-free life.

Have Questions about Your Pet’s Allergies? 

Schedule an appointment with your primary care veterinarian or visit our Burbank or Koreatown location if your pet has concerning symptoms. 

Call us at (818) 296-0700 in Burbank or (323) 302-5200 in Koreatown to speak with a member of our care team. We’re here to help for your furry loved one’s medical needs!