Yellow young Labrador Retriever dog lying in the green grassYellow young Labrador Retriever dog lying in the green grassYellow young Labrador Retriever dog lying in the green grass
Pet Allergies
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Common pet allergies and how to treat them

Just like humans, pets can suffer from all sorts of allergies, including hay fever. Having an awareness of which allergens can trigger a reaction in your pet and knowing how best to treat their symptoms can help you manage their allergy effectively and enable them to carry on enjoying everyday life as normal.

Atopic allergies (such as hay fever)

Atopic allergies most commonly affect dogs and cats over six months old and occur when particles from allergens such as pollen, dust and mold are inhaled or penetrate the skin through the pores. Hay fever is a common atopic allergy which is seasonal, causing the greatest problems when pollen counts are high during summer and early fall. Dust and mold allergies can affect pets all year round, and so monitoring when your pet’s symptoms occur can help to determine the cause.


Itchy skin

The most common symptoms of an atopic allergy are itchy and inflamed skin, rashes, dryness and hair loss. Your pet may scratch, chew and lick their skin, rub up against surfaces and objects, and even lie on cold surfaces to soothe the irritation.

If left untreated, skin irritations can lead to open wounds and skin infections, so keep an eye on your pet’s behavior, check for rashes and redness, and visit your veterinarian if you believe your pet’s skin may be infected.

Watery eyes

Airborne allergens can irritate your pet’s eyes and even cause conjunctivitis. Redness and swelling around the eyes, excessive watering and squinting are all symptoms of allergic conjunctivitis, and this may also be accompanied by discharge, which can vary from clear and watery to thick and greenish.

Allergic conjunctivitis can be diagnosed by a veterinarian and is easily treated with medicated eye drops.

Runny nose

A runny nose is also a common symptom of an allergic reaction caused by airborne particles. Transparent mucous, rather than a thick green or yellow discharge, provides a good indication that your pet’s runny nose is the result of an allergy rather than a respiratory infection.

Respiratory problems

Some airborne allergens can cause your pet’s immune system to produce histamines, which in turn cause the respiratory tract to swell. This can result in breathing difficulties, coughing, panting, wheezing and sneezing.

It is possible to treat a runny nose and respiratory problems with antihistamine medication. However, you should always seek veterinary advice before administering any medication to your pet.


Your veterinarian may recommend blood or intradermal testing to help determine the exact cause of the allergy, and the treatment of symptoms will often last the duration of your pet’s lifetime. However, once you have a better idea of which allergens are triggering a reaction, there are several things you can do to minimize your pet’s exposure to them:

  • The pollen count tends to rise during hot weather and is at its highest in the mornings and evenings, so try and keep windows and doors closed and avoid walking your dog at these times. 
  • Keeping your pet away from plants, flowerbeds and freshly-mown grass, and wiping their face and feet with a damp cloth when they come inside will help remove allergens from their skin.
  • Grooming and clipping long hair helps remove pollen and other allergens from fur, and using specially formulated shampoos can help soothe irritation. Regularly vacuuming and washing bedding can also help reduce allergens in the home.
  • If your pet’s symptoms are particularly severe, your veterinarian may recommend allergy shots - a treatment which involves administering small amounts of the allergen over time so that your pet builds up immunity. 

Flea allergies

Flea allergies are more common when the weather is warmer and flea numbers peak. Flea bites can cause itching in many pets, however some pets may develop an allergy to flea saliva, resulting in inflammation and extreme irritation. It is important that a flea allergy is diagnosed and the symptoms treated as soon as possible.


Signs of a flea allergy include severe itching and hair loss. The hind end is normally the most affected area, and your pet may scratch and bite the areas around their back legs, tail and abdomen. Infections can also develop in broken skin if the symptoms are left untreated.

Your veterinarian can perform a simple skin test to determine whether your pet is suffering from a flea allergy, and the symptoms can be soothed with antihistamine medication or medicated baths.


Having a regular flea treatment program in place is essential for pets that are sensitive to flea bites, and also treating your pet’s environment can help to prevent infestations.

  • Treat all pets in the household with flea control products all year round. There are a number of oral and topical medications available, however it’s important to remember that topical flea medications are not water resistant, so speak to your veterinarian for advice on the best products to use.
  • Fleas can survive without a host for many months, so washing bedding regularly and throwing away the dust bag after vacuuming will help to eliminate fleas from your home.

Insect bites and stings

Insect bites and stings are common, particularly during the summer months. Reactions to bites and stings can vary from mild to severe, so it’s important to monitor your pet closely if you believe they may have been stung. Ideally, you should be able to identify the signs and recognize when it’s time to seek emergency treatment.


You pet is more likely to get stung around the face or paws, and the sting will tend to be accompanied by redness and localized swelling and itching. 
In the case of an allergic reaction, your pet may experience major swelling, breathing difficulties, sickness and general weakness, and they will require emergency veterinary attention. If your pet has been stung on the neck or inside the mouth or throat, it’s important that you take them to your nearest veterinarian straight away.


Mild stings

Bathing the sting in cold water or holding an ice pack against it for 15 minutes will help to reduce the swelling and itchiness, which will then help you to determine the cause of the sting.

  • Ant bites often do not cause an allergic reaction, and the itchiness should subside after 10-15 minutes.
  • If your pet was stung by a wasp, there may be multiple stings. Wasp stings are alkaline, and can be treated effectively at home with lemon juice or vinegar.
  • If your pet was stung by a bee or a hornet, there will just be a single sting; however you will need to remove the stinger from the skin if you can by scraping straight across the skin with a sharp plastic edge. Attempting to squeeze the stinger may result in more venom being released into the skin. Bee and hornet stings are acidic, and so can be neutralized with a solution made from bicarbonate of soda and water.

In the case of a mild sting, the swelling should subside after a few days and you will just need to monitor your pet to ensure they don’t lick or bite the wound, which could potentially lead to infection. If the swelling does not go down, then consult your veterinarian for advice.

Severe reactions

If your pet’s symptoms do not improve and you believe they may be experiencing an allergic reaction, it’s important to seek advice from your veterinarian. They may prescribe antihistamines to help treat the symptoms, or in cases of anaphylaxis, which are extremely rare, your pet may require an epinephrine shot to control the swelling of the respiratory tract and enable them to breathe properly.

Is Benadryl safe for treating my pet’s allergies? Advice from Trupanion veterinarian, Dr. Sarah Nold

Diphenhydramine Hydrochloride, more commonly known as its trade name, Benadryl, is an effective antihistamine medication used to treat allergies in humans. But is it safe for your pet? Trupanion veterinarian, Dr. Sarah Nold offers advice on what Benadryl can be used for and whether it is suitable for treating your pet’s allergies.

  • Benadryl is primarily used to treat the symptoms of atopic and flea allergies, as well as bites and stings. However, it can also be used to help prevent motion sickness, as a sedative or as an anti-vomiting medication.
  • Benadryl should be used with caution, and only with your veterinarian’s approval if your pet has glaucoma, prostatic hypertrophy, hyperthyroidism, cardiovascular disease or hypertension (high blood pressure). It is also not recommended for working animals as it can cause drowsiness.
  • Benadryl may interfere with some types of testing, such as allergy testing. It may also interact with some types of pain relief medication, sedatives or behavior modifiers, so it is important to make your veterinarian aware of any other medication your pet is taking. 
  • Only the pure form of Diphenhydramine Hydrochloride is safe for your pet, so it is vital that you select a form of Benadryl that does not contain other medications for cold or sinus symptoms. Show the packaging to your veterinarian if you are unsure.
  • Your veterinarian will be able to advise you on the appropriate dose and frequency for your pet’s weight, age, and health. While Benadryl can be safe and effective for treating allergies, always check with your veterinarian before using it or if you have any concerns.