Pets with allergies: symptoms, treatments & insurance

12 September 2022 - 8 min read
Itchy dog chewing rear end
Itchy dog chewing rear end

If your dog is waking you up at night licking, chewing, and scratching themselves, we need to talk. Allergies are one of the most common reasons pet parents bring their animals to see us at the clinic.

A lot of owners assume it's allergies, which is common. Experts estimate that 1-2% of dogs have food allergies, while the figures for all allergies are likely higher; some experts think up to 20% of dogs have one. 

However, you must always take your pet to the vet for an official diagnosis. It may not be allergies, and it could be another issue like parasites.

Let’s look at the three major causes of true underlying allergies in pets, why skin problems can be frustrating for pets and owners, and what we can do together to manage allergies in our itchy pets.

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What's an ‘allergy’?

An allergy is the overreaction of your pet’s immune system to something that would not bother another animal. Reactions mainly occur to proteins found in plants (like pollen) or other animals (like chicken meat), which we call allergens. 

Dogs can encounter allergens in the environment through inhalation or eating them. When ingested, they can cause affected animals to release histamines. Histamines cause many issues associated with allergies, including inflammation, itchiness and swelling.

The term allergies can also be used to describe a group of clinical signs, such as itchy skin, itchy eyes or a runny nose.

We also use the word allergy to refer to animals that suddenly develop hives from certain foods, insect bites or the grass at the park.

More severe allergies can cause such a big reaction that your pet can start to have trouble breathing or have hazardous drops in blood pressure. This is called anaphylactic shock and is very uncommon compared to the other reaction types.

Symptoms of allergies in pets

Dalmatian relaxing on a carpet. He has some conjunctivitis causing black run marks under his eyes. He is also looking soulfully out of shot.

Allergic pets can manifest symptoms in many ways, some more obvious than others.

Many pet owners recognise a pet is itchy when they are constantly scratching themselves, but here are some other signs of common symptoms of allergies in pets:

Skin issues

Skin allergies are easier to identify, and there are several symptoms. A pet experiencing a skin allergy may have: 

● red, itchy skin 

● alopecia (hair loss)

● darkened and thickened skin 

● behavioural changes, like overgrooming, excessive itching and saliva-stained spots

● hot skin or inflammation (dermatitis)

● spots, scabs or sores

● ear infections (we’ll explore the symptoms of this below)

The causes for these are wide, with a whole variety of environmental allergens, fleas and food proteins all potential triggers          

Digestive problems

Symptoms of digestive allergies include: 

● vomiting and diarrhoea 

● weight loss

● abdominal pain      

● lethargy

● flatulence

The most acute of these is vomiting and diarrhoea. However, the condition can mean a multitude of things, so it’s important to always seek veterinary advice when in doubt. Read our mythbuster on vomiting and diarrhoea here

Respiratory symptoms

Much like humans, the signs of respiratory illness in pets include: 

● a runny nose

● sneezing

● coughing

● wheezing

A pet may also have eye discharge, excessive panting or sudden onset or worsening in snoring. As these symptoms can be seen in other conditions too such as Kennel Cough, it’s important to get your pet checked over by a vet if you are concerned about them.      

Eye irritation

Eye allergy symptoms include: 

● pawing at the eyes

● puffy, squinted or watery eyes

● discharge

● redness

● sneezing 

Symptoms largely depend on the allergen, but in the case of pets, it’s usually something environmental like pollen or mould. 

Ear infections 

Ear allergies manifest as: 

● excessive scratching

● head shaking

● erythema (or skin redness)

● swelling

● pain, usually communicated via vocalisation 

● excessive odour 

● build-up of fluid or wax

For more, read our guide on ear infections in dogs.

Are certain breeds more likely to have allergies?

Yes. Most dog breeds have a list of illnesses they’re more susceptible to, and allergies are no different. 

Dog breeds prone to allergies

● Boston Terrier

● Boxer

● French Bulldog  

● Golden Retriever 

● Labrador Retriever

● Lhasa Apsos

● Scottish Terrier

● Shar-Pei

● Shih Tzu

● West Highland White Terrier

● Wirehaired Fox Terrier

However, it’s important to note that any dog can suffer from allergies - it’s not exclusive to this list. 

Cats are also susceptible to skin allergies, but this is seen less frequently than in dogs.

How do I know what’s causing my pet’s allergies?

As mentioned, some itching and scratching can be normal. A dog or cat will inevitably need to scratch occasionally or even be mildly irritated by environmental changes. However, there is a portion of itchy pets that do have underlying allergies.

There are three major categories of things that cause truly allergic pets.

Fleas & Insect Bites

When diagnosing an itchy pet, your vet will want to start by ruling out parasites as the cause. Mites may cause itchiness in pets, and your vet may take a sample of your pet's skin to make sure there aren't any mites present.

Fleas are the major parasite responsible for an allergy in our pets. They can irritate any animal, but some pets are allergic to flea saliva. This means their immune system releases compounds that cause itchiness and inflammation in response to flea bites, which can cause major hair loss, redness, skin infections, etc. We refer to this as flea allergy dermatitis or FAD.

My first step when working on an itchy pet is to make sure they are on regular vet-approved flea prevention, so we can take fleas out of the equation.

If you’ve taken your pet out on a walk recently and they’ve suddenly started showing symptoms, it could be insect bites, so keep an eye out for those. Read our in-depth guide on insect bites here if you need any help.

Pet Food Allergies

A lot of owners jump to food as the cause of allergies in their pets. While this could be true, most dogs have environmental allergies (or a combination of both food and environmental).

While many people believe that food allergies are caused by grain, the real culprit is the diet’s protein source. This means commonly encountered meats like chicken, turkey, beef, venison, duck, etc. Some animals can indeed be sensitive to things like wheat or corn, but the majority of our true food-sensitive pets are reactive to the protein.

The only way we can determine if a pet is food allergic is to do a diet trial with a novel protein or hydrolysed protein diet.

A novel protein is a protein source the pet has never had before, while a hydrolysed protein is a broken-down protein source, so it is less likely to stimulate the immune system.

Diet trials can be challenging for owners because the pet has to eat only the diet trial food for eight to 12 weeks, so everyone has to stick to it - with no treats or table scraps. At the end of that period, we assess the pet's symptoms and challenge the diet by adding one new thing at a time to see if the itchiness worsens or recurs.

This helps us plan what the pet can safely eat long-term without causing severe symptoms.

Yes, there are blood tests that check for food allergies, but unfortunately, these are not super accurate, so food trials are used to confirm a diagnosis.  

It’s important to know what’s what when it comes to feeding your pet, including what’s myth, what’s fact and what you should feed them. Read our pet food myths guide to know more.


Your pet may be sensitive to that big, beautiful world out there. Possible allergens include things like grasses, pollens, dander, or dust mites.    

A blood test can be done to determine what types of environmental allergens are an issue for your pet.

The most accurate way to determine what allergens are bothersome is with intradermal skin testing by a specialist veterinary dermatologist. They do testing just like in humans to grade your pet's reaction to common allergens.

The end goal of allergy testing is to formulate allergy immunotherapy specific to your pet. This is usually the form of long-term injections to slowly help desensitise your pet to the things that are causing their symptoms.

In addition to immunotherapy, there are lots of other medications available that can help manage the symptoms of an allergic pet. These include both topical things like creams or shampoos, as well as oral or injectable medications. Chatting with your vet can help determine what regimen works best.

Allergen type Examples
Contact Cleaning sprays, dust, flea saliva, plants
Environmental Dust mites, pollen, mould, spores
Food Beef, chicken, dairy, eggs, fish, soy and wheat
Inhalant Chemicals, perfumes

My dog's allergies came back. Why?

We have a lot of clients express frustration with their allergic pets needing repeat trips to the vet. I completely understand this frustration, as I have a dog with allergies at home.

An important concept that vets try to make clear to pet owners is that we cannot cure allergies, but our goal is to decrease the number of flare-ups they have and make those symptoms less severe when they do happen.

Affected pets also commonly develop secondary bacterial or yeast infections which require treatment. This means we have to make sure we are taking care of the primary issue (itching) and the secondary issues (infections) to have success.

Allergies are a condition you manage over time rather than a one-and-done treatment scenario. Because of this, pet parents must understand that finding a regimen that works for your pet can take some time and some tweaking. But doing so will help you and your pet in the long run.

When to see your vet for allergies

If you notice any of the above signs of itching in your pet, it may be time to call your vet. Redness, hair loss or skin lesions all indicate a problem that needs urgent medical attention. Similarly, if your dog has any signs of an ear infection, breathing difficulties or ongoing digestive troubles, then take them to the vet for an examination.

Can pet insurance cover allergies?

Allergies will often be something you need to manage for the rest of your pet’s life. 

This can get expensive, but if you have pet insurance in place before your vet starts investigating the allergies, it can help cover the cost.

Some pet insurance policies are time-limited, meaning they’ll only cover a condition for 12 months, and after that, you’ll have to pay for it yourself.

All ManyPets policies are lifetime pet insurance, where the vet fee limit refreshes yearly when you renew your policy. This type of cover is good for long-term or chronic conditions like allergies.

In 2021, ManyPets had over 11,000 claims for allergic conditions, including flea allergy dermatitis, food allergies and atopic dermatitis (environmental allergies). The average claim cost was £215.86.

Lots of pet owners will need to claim several times a year, so you can see how the cost would stack up without the right cover.

A person high fiving a dog

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How can I help my allergic pet at home?

While truly allergic pets will likely need long-term support from your vet, there are some things pet owners can do to help:

If your vet prescribed medication to help treat your pet's skin, finish the entire course of medication. Even if the symptoms get better before the end of therapy.

  • Keep your pet on regular parasite prevention (monthly, all year round)

  • Avoid allergens you know your pet is sensitive to if you can (e.g.certain food types)

  • Ring your vet for help before symptoms get severe. If secondary infections are present, they can be easier to get rid of the sooner we address them

  • Ask your vet if supplements to help improve your pet’s skin and coat condition may be of benefit

If you need ongoing medication to soothe your pet's allergies, you could check if an online pharmacy can dispense your prescription. Medicine is often delivered quickly, and it's more affordable in the long run.

There are so many ways to keep your itchy dog or cat comfortable now – work with your vet to come up with a management plan and be vigilant of any changes in your pet’s symptoms so you can act fast to stop things from escalating.

Veterinary surgeon Dr Kirsten Ronngren joined ManyPets in 2022. Alongside her extensive experience as a vet in small animal and feline-only clinics, Kirsten is passionate about online content creation. Kirsten’s a regular on ManyPets’ social media and video content with her no-nonsense attitude to keeping our customers’ pets happy and well.