Did you know that allergies affect animals the same way they affect people? They can affect your pet’s skin, ears, and gastrointestinal tract, and may affect them seasonally or year-round, depending on the cause. Our team at Neighborhood Veterinary Centers of NASA knows that seeing your pet experience an allergic reaction can be upsetting and that their allergen response can range in severity from minor to life-threatening. We explain common allergens that affect pets, signs to watch for, and what to do if your pet develops an allergic reaction.

Allergens and allergic reactions in pets

Allergic reactions are caused by the immune system overreacting to a foreign substance (i.e., allergen) and occur when a pet’s body overreacts and treats them as foreign invaders, resulting in inflammation. Pets can suffer from the same allergies as people, and are often allergic to multiple allergens, making it challenging to determine the trigger. Some of the most common allergies that affect pets include:

  • Flea allergies — Pets who have a flea allergy are hypersensitive to the protein in flea saliva, and can develop a severe reaction to bites from only a handful of fleas. Flea bites cause itching, irritation, and hair loss in adult pets and can transmit harmful diseases to pets and people. Veterinary-approved flea prevention administered year-round is critical to prevent allergic reactions and to keep your pet comfortable.
  • Environmental allergies — Atopic dermatitis, or environmental allergies, can make your pet miserable year-round, or only during certain seasons. Common environmental allergens include:
    • Grass, weed, and tree pollens
    • Mold spores
    • House and dust mites
    • Biting or stinging insects (e.g., ants, flies, bees, mosquitoes)
    • Pet dander
    • Fabrics
    • Plastics
    • Smoke
    • Cleaning products
    • Air fresheners and perfumes
    • Shampoos and other topical treatments
    • Prescription medications
  • Food allergies — Contrary to popular belief, food allergies are not common in pets, but the most likely culprits are proteins like chicken, dairy, beef, and fish, and sometimes carbohydrates.

Allergic reaction signs in pets

Allergic reactions range in severity from mild skin irritation to shock and collapse. It’s important to identify the signs quickly so you can get your pet the relief—and in severe cases, emergency care—they need. Mild to moderate signs include:

  • Reddened, inflamed skin
  • Scratching, licking, chewing, and rubbing at itchy areas
  • Hives
  • Hair loss
  • Thickened skin caused by chronic inflammation
  • Skin infections
  • Hotspots
  • Ear inflammation and infections
  • Anal gland inflammation and impaction

What to do if your pet has an allergic reaction

Follow these steps if you suspect your pet is having an allergic reaction:

  • Identify the trigger — Determine the allergic reaction’s trigger, such as a bite, sting, or cleaning product your pet may have come into contact with. If your pet is bitten or stung by an insect, removing the bug or stinger is key to stopping the progression of the allergic reaction.
  • Consider the severity of your pet’s allergic reaction — Mild to moderate allergic reactions typically can be treated on an outpatient basis with antihistamines and steroid anti-inflammatories, while severe reactions require immediate veterinary care. 
  • Keep your pet calm — An allergic reaction can cause your pet a great deal of discomfort and make them anxious and agitated, which can worsen breathing issues. Keep your pet calm, and move quickly to treat their reaction.
  • Monitor your pet — If your pet’s condition appears to worsen quickly, or they show signs of a severe systemic reaction (i.e., anaphylaxis), seek emergency care right away. Anaphylaxis signs include:
    • Rapid or excessive swelling of the face, eyelids, ears, and muzzle
    • Extreme lethargy
    • Excessive drooling
    • Vomiting or diarrhea
    • Breathing difficulties
    • An elevated heart rate
    • An abnormal heart rhythm
    • Collapse
  • Consult your veterinarian — While a pet’s allergic reaction isn’t always an emergency, your veterinarian can examine your pet and suggest a safe and effective treatment to relieve their discomfort. Treatment for anaphylaxis is more complex, and anaphylactic pets often need epinephrine, intravenous (IV) fluids, supplemental oxygen, a breathing tube, and additional supportive medications. Affected pets often are hospitalized for continued supportive care until they are stable enough to go home. 

How to manage chronic allergies in pets

Determining the exact trigger of your pet’s allergies can be a challenge because many pets have reactions to more than one allergen. Pet allergies are also often chronic and tend to worsen with age. Your veterinarian may use several methods—including intradermal testing, blood testing, and food trials—to diagnose the allergens that affect your pet and can suggest a variety of management techniques and products to manage them long-term, such as:

  • Medicated shampoo
  • Regular ear cleanings
  • Antihistamines
  • Corticosteroids
  • Allergy medications (e.g., Apoquel, Cytopoint)
  • Skin supplements
  • Prescription diets
  • Immunotherapy

Allergic reactions can be alarming, but knowing what to do can help you react quickly and appropriately to keep your pet safe. If your pet is experiencing an allergic reaction, contact our team at Neighborhood Veterinary Centers of NASA for guidance.