Cat itching from allergies

Dealing with your pet’s allergies

Just like humans, pets can suffer from allergies. A variety of irritants can bring on an allergic reaction in a cat or dog.

Allergies are no fun for anyone, and that includes your pet. The three most common triggers of pet allergies are fleas, airborne environmental irritants, and certain foods.1 Just a few flea bites can trigger intense scratching, especially in a pet that’s sensitive. Outdoor and indoor environmental allergies can be triggered by all kinds of insects and substances. And even the diet they eat can affect an allergic pet.

Outdoor allergens1

If your pet only shows symptoms in spring, summer, or fall, he may be allergic to something he encounters outdoors, such as:

  • Fleas and ticks
  • Insect bites (spiders, flies, wasps, etc.)
  • Pollen from trees, grass, flowers, and weeds

However, it’s important to note that while ectoparasites can impact pets during winter, they are more frequent in other seasons.

Indoor allergens1,2, 3

When your pet’s symptoms continue year-round, it could be something he’s encountering indoors. Although most animals find these common substances harmless, they can trigger an allergic reaction in others:

  • Dust and dust mites
  • Mold spores
  • Mildew
  • Household cleaning products
  • Dander
  • Fragrances
  • Cigarette smoke
  • Some prescription drugs
  • Some flea-control products

Potential food allergens4

Your pet can develop food allergies at any age. An elimination diet, in which certain foods are removed and then gradually reintroduced, can help identify what’s causing the problems. Elimination diets should always be supervised by your veterinarian. And remember, treats, table scraps and supplements count too.

Once the symptoms cease, the veterinarian will advise you how to reintroduce former foods to see which may have caused the allergic reaction. Possibilities include:

  • Beef
  • Chicken
  • Fish
  • Pork
  • Corn
  • Wheat
  • Soy

Your veterinarian may recommend or prescribe specially formulated food for your pet that’s designed to address food allergies.

Symptoms of pet allergies5

Your pet may experience respiratory and digestive symptoms as her body tries to rid itself of allergens, but many pet allergies manifest as skin irritation. Signs include:

  • Itchy, red, moist, or scabbed skin
  • Constant licking
  • Itchy ears and ear infections
  • Paw chewing/swollen paws
  • Runny eyes
  • Sneezing
  • Itchy back or base of the tail (most commonly from a flea allergy)
  • Vomiting
  • Diarrhea

Dogs with allergies will often lick and scratch a part of their body until they develop a “hot spot.” Without treatment, skin infections can develop and may cause hair loss.

Cats suffer most of the same symptoms. Additionally, some may be allergic to their litter (switching to a dust-free alternative may solve that issue). Asthmatic cats may cough and wheeze in response to irritants.

How pet allergies are diagnosed5

Allergies occur in all breeds and the symptoms typically appear after a cat or dog reaches six months of age.

Your veterinarian may be able to determine the source of your pet’s allergic reaction from a physical examination and may recommend a skin or blood test or a specific elimination diet to find out what’s causing the reaction.

If the initial treatment doesn’t clear up your pet’s irritated skin, a visit to a veterinary dermatologist may be in order. As with humans, an allergy specialist may conduct a patch test, in which small amounts of specific potential allergens are applied to your pet’s skin to see which (if any) cause a reaction.

Treating a pet allergy1

Because some irritating substances are difficult or impossible to eliminate from the environment, your veterinarian can recommend ways to control an allergic reaction. Common treatment options include:

  • Cortisone or steroids
  • Itch-blocking medications
  • Antihistamines
  • Flea prevention products such as BRAVECTO® (fluralaner)
  • Allergy shots
  • Hypoallergenic or medicated shampoos and conditioners, since bathing may help relieve itching and remove environmental irritants from your dog’s skin
  • Omega-3 supplements to help suppress itching
  • Veterinarian-supplied medicated spray
  • Pet allergen-blocker wipes to use on paws when outdoor dogs and cats come indoors
  • Specially formulated pet food to address food allergies

Environmental allergies can be managed but not cured, so it’s essential to bring your pet in for check-ups to assess how he responds to treatment and adjust it as needed so that your pet can stay as comfortable as possible.


  1. Weir, Malcolm. Allergies in Dogs. VCA Animal Hospitals.
  2. Dust Mites: Minimizing Exposure in Dogs and Cats. Veterinary Partner.
  3. Poisonous Household Products. American Society for the Prevention of Cruelty to Animals.
  4. What every pet owner should know about food allergies. Tufts University.
  5. Burke Anna. Dog Allergies: Symptoms and Treatment. American Kennel Club.


BRAVECTO 1-MONTH (fluralaner) Chews: indicated for dogs 8 weeks of age and older. The most commonly reported adverse reactions include itching, diarrhea, vomiting, decreased appetite, elevated ALT, lethargy, and weight loss. BRAVECTO 1-MONTH (fluralaner) Chews is not effective against A. americanum in puppies less than 6 months of age. BRAVECTO (fluralaner) Chews: The most commonly reported adverse reactions include vomiting, lethargy, diarrhea, anorexia and pruritus. In some cases, adverse events have been reported following use in breeding females. BRAVECTO (fluralaner topical solution) for Dogs: The most commonly reported adverse reactions include vomiting, hair loss, diarrhea, lethargy, decreased appetite, and moist dermatitis/rash. BRAVECTO (fluralaner topical solution) for Cats: The most commonly reported adverse reactions include vomiting, itching, diarrhea, hair loss, decreased appetite, lethargy, and scabs/ulcerated lesions. BRAVECTO (fluralaner topical solution) for Cats is not effective against American dog ticks beyond 8 weeks of dosing. BRAVECTO PLUS (fluralaner and moxidectin topical solution) for Cats: The most commonly reported adverse reactions include vomiting, hair loss, itching, diarrhea, lethargy, dry skin, elevated ALT, and hypersalivation. BRAVECTO PLUS (fluralaner and moxidectin topical solution) has not been shown to be effective for 2 months in kittens less than 6 months of age. Use with caution in cats that are heartworm positive. The effectiveness of BRAVECTO PLUS (fluralaner and moxidectin topical solution) to prevent heartworm disease after bathing or water immersion has not been evaluated.

BRAVECTO (fluralaner) has not been shown to be effective for 12-weeks’ duration in puppies or kittens less than 6 months of age. BRAVECTO (fluralaner) Chews and Topical Solution for dogs is not effective against the lone star tick beyond 8 weeks of dosing. BRAVECTO (fluralaner topical solution) for Dogs and Cats and BRAVECTO PLUS (fluralaner and moxidectin topical solution) for cats are for topical use only. Avoid oral ingestion. The safety of BRAVECTO (fluralaner topical solution) for Cats and BRAVECTO PLUS (fluralaner and moxidectin topical solution) has not been established in breeding, pregnant, and lactating cats.

All BRAVECTO (fluralaner) products contain fluralaner, which is a member of the isoxazoline class.  This class has been associated with neurologic adverse reactions including tremors, ataxia, and seizures. Seizures have been reported in dogs receiving isoxazoline class drugs, even in dogs without a history of seizures. Use with caution in dogs with a history of seizures or neurologic disorders. Neurologic adverse reactions have been reported in cats receiving isoxazoline class drugs, even in cats without a history of neurologic disorders. Use with caution in cats with a history of neurologic disorders.

Want to share this article?

More like this

Bravecto advertisement