Humans aren’t the only ones who suffer during allergy season—pets develop allergies too. Rather than a runny nose or itchy eyes, pet allergies most often cause chronic skin and ear problems. Veterinarians often repeat the ears, rears, and feet mantra, describing pets’ main body regions that allergies often affect. Our Neighborhood Veterinary Centers teams frequently treat allergies, and we often have discussions with owners who have misconceptions about their pets’ allergy origins and management. Here, we describe everything you need to know about allergies in pets. 

Allergy signs in pets

Allergies are a complex and inappropriate immune response to something in the environment, or less commonly, in a pet’s diet. Depending on the individual pet, these hypersensitivity reactions can develop at various speeds, and with differing severity levels. Pets’ allergies rarely include typical hay fever-like signs, but most often manifest in the skin and associated structures. Pets usually show their first allergy signs between 6 months and 3 years of age, but new allergies can emerge later in life. Depending on the underlying allergens, a pet’s signs can be year-round or seasonal. Dogs’ and cats’ allergy signs most often include:

  • Itching—demonstrated by licking, scratching, chewing, biting, or rubbing
  • Red, dark, or thickened skin patches
  • Hair loss
  • Skin infections and rashes
  • Skin sores or crusting
  • Recurrent ear infections
  • Recurrent anal gland problems
  • Vomiting or chronic diarrhea

Allergy types in pets

Three different allergy types—flea, environmental, or food—can affect pets. Flea allergy is the most common dermatologic disease in dogs, and environmental allergies are close behind. Contrary to popular pet food marketing claims, food allergies in dogs and cats are rare. 

Pets’ environmental allergies can be to just about anything, but most often include pollen, dust, mold, insect bites, dust mites, storage mites, or dander from other animal species. Food allergies are most often to a food protein, including beef, chicken, egg, fish, lamb, dairy, soy, wheat, or corn. Most pets with one allergy type are likely to develop others, and many suffer from multiple allergy triggers that may change throughout their lifetime.

Allergy diagnosis in pets

Your veterinarian will usually diagnose your pet’s allergies on physical examination, after ruling out other common skin diseases such as parasites or infections. While your veterinarian may determine your pet is suffering from allergies, determining the exact underlying allergen is more difficult to pinpoint. Your veterinarian may recommend various treatment trials to assess your pet’s response, which can provide clues to the underlying allergen. Your primary veterinarian may also refer your pet to a veterinary dermatologist, who can perform blood or skin tests to check for specific environmental allergens. A food allergy is more difficult to identify and requires a trial with a specific diet.

Allergy treatments for pets

Because each pet has a different allergy trigger, for your veterinarian to determine your furry pal’s unique treatment will take some trial and error. Your veterinarian’s first step will be to treat fleas. They will place your allergic pet on monthly year-round flea prevention medication. Other allergy treatments may include:

  • Anti-itch or anti-inflammatory medications — Allergies cause inflammation, which results in itchy, red skin. Medications such as Apoquel, Cytopoint, prednisone, and Atopica are useful to stop the itch-scratch inflammatory cycle.
  • Antibiotics or antifungals — Secondary infections are common in an allergic pet, which their veterinarian will treat with oral antibiotic or antifungal medications.
  • Topical medications — Topical sprays or ointments can be helpful to reduce oral medication use and are especially useful when a pet’s ears are infected or inflamed.
  • Medicated shampoo — Shampoos are a mainstay in allergy therapy and help reduce inflammation and harmful bacteria on the skin. Most allergic pets need medicated baths several times per week when their allergies are at their worst.
  • Allergy immunotherapy — Exposing a pet’s body to increasing—but controlled—levels of their allergens can result in desensitization over time. This treatment is effective for around two-thirds of pets, but can take up to a year to be fully effective.
  • Hypoallergenic diet — If food is a suspected allergy trigger, your veterinarian will place your pet on a strict elimination diet to see if their signs improve. If effective, the diet can be continued long term, or your veterinarian can challenge your pet with individual foods to pinpoint the culprit.

Allergy prevention in pets

Researchers aren’t sure exactly why some pets develop allergies and others don’t, although your pet’s breed may predispose them to certain allergens. Recent research suggests that a pet’s gut bacteria (i.e., microbiome) may have a big impact on their immune function and allergy development, but we are far from completely understanding how this works. For now, no proven strategies exist to prevent allergies in pets.

Many pets suffer from allergies, but proper treatment and management can provide long-term relief. Find the Neighborhood Veterinary Centers location nearest you, and schedule your pet’s skin examination and allergy consultation.