Stop the itch: How to treat allergies in cats and dogs

If your cat or dog seems to be itching and scratching incessantly, or has a cough and nasal congestion, they might be suffering from allergies. Just like their owners, pets can be allergic to dust mites, pollen, mold, insects and more.

Make an appointment with a veterinarian at the first sign of allergy symptoms to identify the source of your pet’s discomfort and to find the best allergy medicine for dogs and cats. If allergies go untreated, wounds and secondary infections can form, which increases your pet’s scratching and discomfort.

What are pets allergic to?

There are three main types of allergies in cats and dogs: insect, food, and environmental allergens.

Insect allergies

The same way that humans can have a severe reaction to a bee sting, dogs and cats can have an exaggerated inflammatory response to bites or stings from insects. These commonly include ticks, spiders, deer flies, horseflies, blackflies, mosquitoes, ants, bees, hornets, wasps, and most commonly, fleas.

For pets that are sensitive to flea saliva, even one bite can trigger severe itching. When your pet scratches, broken skin can become infected and lead to even further itching and chronic wounds.

Food allergies

Cats and dogs can experience food allergies. “Pets can be allergic to individual proteins or grains in their food such as beef, dairy, wheat or chicken” says Lara Sypniewski, DVM, a clinical professor at Oklahoma State University College of Veterinary Medicine. This type of allergy can cause skin irritation, gastrointestinal issues, and respiratory problems in severe cases.

Environmental allergies

Environmental allergens are one of the main causes of allergies in pets, including pollen, mold, grass, and weeds, explains Rosanna Marsella, DVM, a professor at the College of Veterinary Medicine at the University of Florida.

Inhaling an allergen can make your pet’s immune system overreact, leading to respiratory symptoms or dermatitis. “Allergic skin disease is a very common diagnosis for dogs and cats,” Dr. Sypniewski says.

Allergy symptoms in pets

The most common symptoms of allergies in cats and dogs are:

• Skin itching, indicated by redness of the skin, paw licking, scratching, or head shaking
• Respiratory symptoms like coughing, wheezing, or sneezing
• Digestive problems such as vomiting or diarrhea

Dr. Sypniewski says pet owners may also notice symptoms such as a pet’s hair loss or skin color changes and crusting. In rare cases, severe allergy can trigger anaphylaxis. If your pet has trouble breathing, seek emergency medical care immediately. This can be life-threatening.

Diagnosing your pet’s allergies

At your veterinarian appointment, your pet will undergo a physical examination and possibly a blood and/or skin test to determine the cause of their allergic reaction. Once your pet’s allergy triggers have been identified, your veterinarian will work with you to form a treatment plan.

Allergy medicine for dogs and cats: What’s safe and what’s not?

Veterinarians take a multi-faceted approach to treating pet allergies. “The first step is to make the dog or cat feel better by treating the clinical signs of an acute flare (i.e., itching, licking) and any secondary bacterial or yeast skin or ear infections,” Dr. Sypniewski says. 

Depending on the allergen, and the reaction it causes, treatment can include:

• Prescription shampoo (antibacterial or antifungal)
• Prescription ear flushes
• Anti-inflammatory topical medications
• Oral antibiotics
• Itch relief medication, such as Apoquel for dog allergies or Atopica for cats
• Injectable monoclonal antibody therapy
• Corticosteroid therapy

“These medications are usually very effective to stop itching quickly, which will improve the quality of life for both the pet and their owner,” Dr. Sypniewski notes. “Veterinarians consider the effectiveness as well as side effects of each of these medications prior to recommending treatment.”

If your pet has mild seasonal allergies without a skin infection, over-the-counter antihistamines might be an option for allergy relief. Benadryl (diphenhydramine), Zyrtec (cetirizine), and Claritin (loratadine) are commonly used allergy medicine for cats and dogs.

“If your veterinarian recommends these medications, it is important to avoid formulas with added ingredients, such as decongestants or pain relievers, as they may be harmful to pets,” Dr. Sypniewski explains. “It’s also important to note that these OTC products are much less effective in dogs and cats than in humans and can also result in side effects such as making your pet drowsy or hyperactive.”

If your pet has severe allergies, allergen specific immunotherapy, commonly known as allergy shots, might be recommended. This is best for young to middle-aged pets with chronic allergic skin disease, says Dr. Marsella. The drawback is it can sometimes take up to a year to realize results. 

Home remedies for pet’s allergies

There are home remedies that can help alleviate certain symptoms. Lifestyle changes that can make a difference include:

• Home improvements: Making your home as hypoallergenic as possible can help. Consider installing an air cleaner with a HEPA filter and cleaning fabric surfaces regularly.
• Soothing baths: “Your veterinarian might recommend … bathing your dog or cat with a pet shampoo that contains oatmeal,” Dr. Marsella explains. (If your pet is on a flea medicine, check with your vet to ensure the topical flea or tick medication won’t be washed away, reducing their effectiveness.)
• Dietary supplements: Supplementing your pet’s diet with fish oil can reduce flaky or itchy skin. “Probiotics can also offer pets relief from skin allergies by restoring balance to bacteria levels in their GI tract,” Dr. Marsella says. “By improving the health of their GI tract, probiotics can help reduce allergy symptoms.”
• Physical blockers: A simple intervention for itchy pets is to have them wear a T-shirt, since it appears it may reduce their drive to scratch, suggests Dr. Sypniewski.

Preventing allergic reactions in pets

The best way to treat allergies is to avoid the reaction altogether. “Management of pet allergies is done by preventing fleas and ticks, avoiding allergy triggers such as dust mites or mold if possible, and dietary restriction for food allergies,” says Dr. Marsella. “Pet owners taking care of an allergic dog or cat should be aware that it requires time and effort on both their part and their veterinary team to effectively manage their pet’s allergies,” she adds.