Allergies in pets typically manifest as itchy skin, and common culprits include fleas, environmental allergens, and food. If your pet is itchy, the constant scratching can result in open wounds and secondary skin infections, and management can be problematic. Our team at Burlington Veterinary Center wants to explain how allergies can affect your pet, and how we determine the cause of your pet’s reaction.

Why is my pet itchy?

Pet owners most commonly seek veterinary attention for pets with itchy skin, and itchy pets are frequently diagnosed with an allergy. Fleas, environmental allergens, and food are the most likely offending agents, and determining the allergy origin is important to ensure the pet receives the appropriate treatment.

How do I know if my pet is allergic to fleas?

Flea allergy dermatitis (FAD) is the most common skin condition seen in companion animal practice, and pets can react to a bite from a single flea, because they are allergic to the flea’s saliva. Finding a flea or flea dirt in your pet’s coat or their bedding makes FAD likely, but your pet’s constant grooming may remove all fleas and flea dirt. Pets with a flea allergy typically show clinical signs that include itchiness involving the lower back, tail base, under the tail, and the thighs, and they may also have hair loss and crusty skin lesions in these areas. A treatment trial may be recommended if your pet is exhibiting flea allergy signs, despite finding no fleas. Flea control recommendations include:

  • Year-round flea prevention — Your pet will be placed on a flea prevention medication, and you must be vigilant in administering the chosen product year-round.
  • Flea control for other pets — Any pets in contact with your pet should also have flea control.
  • Treat your home — You may need to treat your home using an insecticide that kills fleas and stops their reproduction. Ensure you remove your pet from the area before spraying, spray all surfaces, and only allow your pet to return when the spray has dried. Washing all bedding, vacuuming carpets and upholstery, and discarding the vacuum bag to prevent flea eggs from hatching in the bag are other important steps.
  • Treat your lawn — If your pet spends time outdoors, you may need to treat your lawn.

How do I know if my pet is allergic to their food?

Pets can be allergic to ingredients in their food, but food allergies are not common in pets. Pets who are allergic to their food are typically reacting to the protein source, such as beef, dairy, eggs, and chicken, which are common culprits. Carbohydrates, such as corn, wheat, and soy, have also been linked to food allergies in pets. Affected pets are excessively itchy, and clues that your pet may have a food allergy include:

  • Non seasonal — Your pet’s signs are not seasonal.
  • Age — Your pet’s signs started when they were less than 6 months or older than 5 years of age.
  • Lesion location — Dogs affected by food allergies are typically itchy, with skin lesions on their face and feet, and recurrent ear infections. Cats affected by food allergies are typically itchy, and have skin lesions on their face and neck.
  • Non-responsive to steroids — Food allergies do not usually respond to empirical treatment with corticosteroids.
  • Accompanying gastrointestinal signs — Signs, such as vomiting, diarrhea, and chronic gas, are seen in about 30% of food allergic pets.

Your pet with a suspected food allergy will be placed on a food elimination trial to determine if an ingredient in their food is causing their reaction. Two options are available when performing a food elimination trial.

  • Novel diet — A novel diet includes one protein and one carbohydrate that your pet has never eaten. Examples include diets based on venison and potato, fish and potato, egg and rice, and kangaroo and pea.
  • Hydrolyzed diet — These diets involve breaking down a conventional protein to small molecules that the immune system cannot identify.

Your pet will need to remain on the trial diet for about eight weeks, and must not ingest any other food, including treats and medicated chews, during this time. If your pet’s signs resolve during the food trial, they can be put back on their original diet, and a food allergy can be officially confirmed if their itchiness returns. Your pet can also be challenged with individual ingredients from their original diet to determine which substance caused their reaction. 

How do I know if my pet is allergic to an environmental allergen?

Environmental allergies in pets are known as atopy. Pets can be allergic to allergens such as pollen, dust mites, mold, and pet dander. Clues that your pet may have atopy include:

  • Seasonal — If signs occur seasonally, atopy is suspected, but some allergens are present year-round, so atopic pets may have signs year-round.
  • Age — Atopic pets typically exhibit their first signs between 1 and 3 years of age.
  • Lifestyle — Most atopic pets usually live indoors.
  • Lesion location — Atopic pets are typically itchy, with skin lesions on their ears and feet, and commonly recurring skin infections.
  • Steroid response — Atopic pets usually respond rapidly to corticosteroids.

If atopy is suspected, allergy testing can determine what environmental allergens are causing your pet’s reaction. Intradermal skin testing or blood tests are available to perform allergy testing, and the information used to create hyposensitization therapy to desensitize your pet to the offending allergens. This involves administering gradually increasing allergen doses, and desensitization can take 6 to 12 months to be effective. Other treatments include weekly bathing to remove allergens, anti-itch medications, corticosteroids, and omega-3 fatty acid supplements.  

An allergic pet’s itchiness can be managed effectively after a proper diagnosis. If you have an itchy pet, contact our Fear Free team at Burlington Veterinary Clinic, so we can determine the cause and alleviate their distress.