Allergies in pets: what you need to know about grass and other allergies

Get the lowdown on allergic reactions in dogs and cats, including environmental allergens such as pollen, parasite-related allergens and food allergens.

Just like us, our dogs and cats can suffer from a variety of allergies. An allergic reaction occurs when an animal’s immune system reacts disproportionately to a substance that’s usually considered harmless (the allergen). When different allergens are inhaled, eaten or absorbed through the skin or the lining of the respiratory tract, this stimulates an immune reaction within the body.

Allergies in cats and dogs – medically known as atopy – occur in response to three types of allergens: environmental allergens, parasite saliva and, less commonly, food allergens.

Here, we look at how to identify, treat and manage each type of allergy to keep your pet as comfortable and carefree as possible.

Environmental allergies in cats and dogs

Our pets can be sensitive to allergens in their environment, both inside and outside the house. Typical outdoor allergens include pollen from grasses, weeds and trees. So, as with human hay fever sufferers, the impact of these allergens on our pets may be heightened in spring and summer.

In the UK, the tree pollen season is generally late March to mid-May; the grass pollen season peaks from mid-May to July; and the weed pollen season kicks in from the end of June to September. So, if your pet is only suffering allergy symptoms (see below) at these times of year, it’s possible that they’re reacting to an external environmental allergen.

With regard to allergens that are found within the home, the most common are dust mites. Invisible to the naked eye, these tiny creatures live year-round in our homes in soft furnishings, bedding, mattresses and pet beds. They deposit a protein in their poo that can cause an allergic reaction in vulnerable pets and people.

Certain types of mould that can occur inside the home are also environmental allergens. Interestingly, everyday household products such as cleaners are unlikely to cause allergies in pets – although of course they may cause other serious health problems when ingested, if they’re toxic to dogs or cats, so be sure to check before you buy.

Symptoms of environmental allergies in pets

Allergies in cats and dogs can cause a spectrum of symptoms, and some animals will demonstrate more of these symptoms than others. Note that the allergy symptoms listed below can also be associated with many other health problems, which can make diagnosing allergies tricky.

  • Excessive itching, scratching, nibbling or licking anywhere on the body – but environmental allergies are particularly likely to affect the ears, rear, feet or face
  • Reddened, inflamed skin, particularly on the above areas
  • Loss of hair, secondary skin infections, scabbing or crusting, caused by trauma from repeated scratching or licking
  • Persistent or recurrent ear infections

Bear in mind that pets who react to environmental allergens are much less likely than humans to experience respiratory symptoms, such as sneezing or sniffles. Instead, their symptoms are more likely to take the form of a skin allergy (atopic skin disease) in cats or dogs, with lots of itching and scratching.

Anaphylactic reactions in dogs and cats

Severe, dangerous allergic reactions in dogs and cats, known as anaphylactic reactions, are rare. An anaphylactic reaction manifests differently to the chronic allergic response resulting from exposure to environmental allergens such as pollen. It tends to be triggered by insect stings, reptile venom or certain medications. Symptoms can include itching, swelling, drooling, vomiting, diarrhoea, breathing difficulties, seizures and coma. If you suspect your pet is having an anaphylactic reaction, seek help from your vet immediately.

Diagnosing environmental allergies in pets

If you suspect your pet has an allergy, you should always take them to see your vet. Allergies in cats and dogs are notoriously hard to diagnose. Your vet won’t be able to make a diagnosis simply by looking at your pet or discussing their symptoms with you, but blood and skin tests can help to identify the problem. With Petplan dog and cat insurance, you’re covered for vet bills and any diagnostic tests your vet recommends, as long as the allergy isn't excluded on your policy – you will find any exclusions listed on your Certificate of Insurance. Terms and conditions apply.

Managing environmental allergies in dogs and cats

Depending on the nature and severity of the allergy, your vet will recommend a range of approaches to manage your pet’s symptoms. Options include medications to control the sensation of itching, as well as other medications that tackle the allergy more directly, such as immunotherapy. This can help moderate your pet’s reaction to allergens, resulting in fewer – or less intense – symptoms.

Never be tempted to skip vet advice and treat your cat or dog with human allergy treatments, as these medicines can be harmful to pets.

While your vet will advise on appropriate medication, there are also a number of things that you can do at home to help ease the symptoms of environmental allergies in cats and dogs:

  • Ideally, keep your pet away from the allergen – but this can be virtually impossible in the case of environmental allergens like pollen. However, you could try keeping your pet indoors during periods when the pollen count is particularly high (and provide indoor cat and dog activities instead). If your dog is allergic to pollen, take them for walks in the early morning, when pollen counts are lower.
  • If a dog or cat with a suspected pollen allergy has been outside, wipe down their coat with a damp cloth as soon as they come indoors to help remove pollen. You can’t prevent them from inhaling pollen while they’re outdoors, but you could stop them licking pollen grains off their coat when they’re cleaning themselves.
  • Bathing your dog regularly can also help remove allergens. While cats don’t usually need a helping hand with keeping clean, the odd bath might be useful.
  • Regular grooming of dogs and cats can also help minimise the build-up of allergens in their coats.
  • Be wary of using topical skin treatments, because your dog or cat will lick them off their coat – ask your vet to advise on suitable medications.
  • Wash your pet’s bedding regularly to reduce dust mites, pollen or other allergens.
  • If your pet has a suspected allergy to dust mites, choose dog and cat beds made with synthetic fabrics rather than natural materials such as feather or wool, and consider replacing their bedding every year. And remember not to let them sleep on your bed or sofa if it’s covered with natural fabrics.
  • Vacuum and wipe down the house regularly to reduce dust and other allergens. Tiled, wood or laminate floors tend to be better for pets with dust-mite allergies than carpet. Dust mites thrive in high humidity, so using a dehumidifier could also help.

Parasite allergies in dogs and cats

One of the most common allergies in dogs and cats is an allergy to the saliva of certain parasites – typically, fleas. Fleas in dogs or cats can be a miserable experience for any animal, but especially for those suffering from a flea saliva allergy, also known as flea allergy dermatitis. When a pet with flea allergy dermatitis is bitten by a flea, their body reacts to allergens in the flea’s saliva. Even a single flea bite can cause a severe reaction in affected animals.

Animals vulnerable to flea allergies can experience symptoms all year round, but as flea populations are higher during the warmer months, spring and summer can be particularly challenging. Don’t forget, however, that fleas live indoors, which means that they can persist around the year. Turning on the heating in autumn or winter can cause a resurgence in flea populations.

Ticks in dogs or cats can also be a source of parasite saliva allergies – be vigilant about checking your pet for these if they’ve been outdoors and may have been exposed.

Symptoms of parasite allergies in pets

The signs of parasite allergies in dogs and cats are similar to those of other allergic reactions: intense scratching, chewing and licking of themselves, which can result in skin irritations, sores, scabs, hair loss and skin infections. However, parasite allergies are more likely to affect your pet’s torso than environmental allergies – in particular, their rump and back.

Managing parasite allergies in cats and dogs

The best way to handle parasite allergies in pets is prevention. In the case of flea allergy dermatitis, that means keeping up with your cat or dog’s regular flea treatments. While there are many flea treatments on the market, their ability to kill fleas quickly varies. This is why prescription-only medications are recommended by vets in the case of flea allergy dermatitis to prevent as many flea bites as possible and bring rapid relief to your pet.

If your vet diagnoses flea allergy dermatitis, they’ll recommend treating your affected pet, and any other animals in the house, with a vet-approved flea medication – as well as treating their environment to remove any pesky fleas, larvae or eggs. In the case of a tick allergy, your vet will be able to advise on preventative tick treatments.

Food allergies in cats and dogs

A food allergy in cats or dogs can occur at any age and your pet must have had previous exposure to the ingredient to develop a reaction to it. If an animal does develop a food allergy, they’ll be allergic to one of the protein molecules in their diet, which are usually found in meat and dairy.

Note that food allergies in dogs and cats are a lot less prevalent than people often think, and certainly less common than environmental or parasite allergies. Food allergies account for around 10% of allergies in dogs and cats.

Symptoms of food allergies in pets

The symptoms of a food allergy in cats or dogs are similar to those of other allergies, including itching of the body, especially the feet and ears. They may also include gastrointestinal problems such as diarrhoea, inconsistent bowel movements and passing mucus or blood.

What foods are cats and dogs allergic to?

The most common allergens in canine diets are the proteins found in meat, such as chicken, beef, lamb and pork. It’s also possible for dogs to be allergic to hen’s eggs, although this is quite rare. Animal intolerances to proteins in wheat, such as gluten, are not impossible, but they are far rarer in dogs and cats than in humans.

Food allergies seem to be less prevalent in cats than in dogs. But as with dogs, the foods that trigger allergies in cats include animal proteins – so meat and dairy.

Managing food allergies in cats and dogs

A food allergy in your pet can usually be managed by altering their diet. Your vet may also prescribe medication to help ease food allergy symptoms. The challenge with food allergies in cats and dogs is diagnosing which particular allergen in their food is causing the problem. Sometimes this can only be done by a process of elimination or by putting your pet on a genuinely hypoallergenic diet and gradually reintroducing their old food to test which might be causing the reaction. It’s essential to get your vet’s guidance on how to do this properly. 

Be wary of so-called hypoallergenic pet foods that are on general sale. If a manufacturer has labelled the product “hypoallergenic” because they’ve taken out wheat, their dog food is definitely not hypoallergenic for a dog that’s allergic to chicken! Many foods marketed as hypoallergenic aren’t sufficient to protect your pet from allergens, so always seek advice from your vet.

Multiple allergies in dogs and cats

Note that pets who have developed one allergy may have a propensity to suffer from others as well. This can complicate the picture when trying to identify, manage and resolve allergies in cats and dogs. For example, your vet may diagnose a food allergy in your dog, but symptoms still persist after cutting out that food, because your dog also has an environmental or parasite allergy.

Investigating allergies can be time-consuming and costly, which is why it's important to have the right pet insurance. If you’re ever worried about continuing, new or worsening symptoms in your pet, always get them checked out by your vet.

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