Caring for a four-legged companion involves much more than evening walks, serving favourite treats or playing together. Above all, it means taking great responsibility for their health and everyday comfort.
One problem that can be easy to overlook at first is an allergy in a dog. Your companion begins scratching more often, licking their paws or rubbing against the carpet. Their skin becomes red, and their ears need treatment yet again. At first, it may appear to be temporary irritation. When the symptoms return or become increasingly troublesome, however, it is worth looking for the cause.
Dogs, like people, can develop hypersensitivity to various factors. The problem may be connected with environmental allergens, food, flea saliva or contact with a particular substance or material. Itching alone does not automatically mean an allergy. Similar symptoms may also be caused by parasites, bacterial and yeast infections, irritation and other skin conditions.
Understanding the subject can spare your companion many weeks of discomfort. The most important point, however, is not to diagnose or treat an allergy solely on the basis of advice found online. Different types of allergies can look very similar, and effective management depends on identifying the correct cause.
What will you learn from this article?
• what an allergy in a dog is,
• which symptoms may indicate an allergic reaction,
• when immediate veterinary help is required,
• how environmental, food, contact and flea allergies differ,
• why scratching alone is not enough to diagnose an allergy,
• what the diagnostic process looks like,
• what can be done safely before visiting a veterinary surgeon,
• whether a dog can be given Zyrtec or Allertec,
• whether human allergy medicines are safe for dogs,
• why this article does not provide a cetirizine dose,
• which methods may help relieve itching,
• whether there are home remedies for allergies in dogs,
• how long symptoms may take to improve,
• whether a puppy can have an allergy.
When is an allergic reaction in a dog an emergency?
Most chronic allergic skin diseases do not develop within a few minutes. Acute reactions do occur, however, and they require immediate help. Do not wait for the symptoms to improve. Contact the nearest veterinary practice if your dog develops:
• sudden swelling of the face, lips or area around the eyes,
• difficulty breathing,
• sudden severe weakness or loss of consciousness,
• very pale gums,
• a weak pulse,
• sudden, intense vomiting or diarrhoea,
• excessive salivation,
• seizures,
• signs of shock.
A severe reaction may occur after an insect sting, medication, vaccination or contact with another allergen. Anaphylaxis is an immediately life-threatening condition and requires urgent treatment. [1]
What causes allergies in dogs?
When looking for the cause of a dog’s poor wellbeing or loss of appetite, we often consider a wide range of serious conditions. In some cases, however, the problem may be a hypersensitivity reaction. An allergy is an abnormal immune response to a particular factor. The body identifies it as a threat and triggers a reaction that can lead to itching and inflammation. The development of allergies may be influenced by:
• genetic predispositions,
• abnormalities in the skin’s protective barrier,
• the way the immune system functions,
• the composition of microorganisms living on the skin,
• contact with environmental or food allergens,
• flea bites,
• secondary skin and ear infections.
The environment in which the dog lives may also intensify existing symptoms. Relevant factors can include pollen, house dust mites, mould, humidity, parasites, detergents and cosmetics. Some breeds are more commonly affected by atopic dermatitis. Predispositions have been observed in breeds including Golden Retrievers, Labradors, Boxers, Dalmatians, Shih Tzus and West Highland White Terriers. Breed alone is not sufficient to make a diagnosis, however, and an allergy can also develop in a mixed-breed dog. [2]
What are the symptoms of allergies in dogs?
The most common symptom of allergic skin disease is itching. A dog may scratch with their paws, bite their skin, lick between their toes or rub their head against furniture and carpets. The symptoms do not always resemble a typical rash. In some dogs, the first sign is a recurring ear problem or intense paw licking.
Look out for:
• frequent scratching,
• licking and biting the paws,
• red skin,
• papules, scabs or flaking,
• localised hair loss,
• skin discolouration,
• darkening of the coat caused by saliva,
• an unpleasant smell from the skin,
• recurrent ear inflammation,
• head shaking,
• rubbing the face,
• moist and painful skin lesions,
• restlessness and difficulty resting.
An adverse food reaction may also cause:
• loose stools or diarrhoea,
• vomiting,
• more frequent bowel movements,
• wind,
• gastrointestinal discomfort.
| Symptom | What might it indicate? |
|---|---|
| Itching of the paws, face, armpits and abdomen | an environmental or food allergy, parasites or infection |
| Itching around the base of the tail and lower back | flea allergy dermatitis, among other possible causes |
| Recurrent ear inflammation | an environmental allergy or adverse food reaction |
| Licking one specific area | irritation, a wound, pain or a skin problem |
| Diarrhoea and itching | a possible food reaction, but also other conditions |
| Sudden swelling of the face | an acute reaction requiring prompt veterinary contact |
The table presents possible explanations rather than a diagnosis. Allergy symptoms can resemble many other health problems.
Does scratching always mean that a dog has an allergy?
No. Itching is a symptom, not a diagnosis of a particular disease. A dog may scratch because of:
• fleas or other parasites,
• a bacterial infection,
• yeast overgrowth,
• skin irritation,
• an insect bite,
• contact with an irritating substance,
• a skin condition unrelated to allergy,
• pain or discomfort,
• an allergic skin disease.
For this reason, the diagnostic process usually begins with a detailed medical history and the exclusion of more common or easier-to-confirm causes of itching. [3]
Types of allergies in dogs
Allergic skin diseases in dogs may have different underlying causes. The diagnostic process most commonly considers flea allergy, food reactions and atopic dermatitis associated with environmental allergens. Some dogs also develop allergic or irritant contact dermatitis.
Importantly, one dog may react to more than one factor at the same time. An environmental allergy does not rule out a food reaction or hypersensitivity to flea saliva.
Flea allergy dermatitis
Flea allergy dermatitis is a hypersensitivity reaction to components of flea saliva. In a sensitive dog, even a small number of bites can cause intense itching. The affected areas most commonly include:
• the lower back,
• the base of the tail,
• the backs of the thighs,
• the abdomen,
• the groin.
The dog may bite their skin intensely, pull out fur and create painful wounds. Not seeing fleas does not rule out the problem — a dog may remove them while grooming, and fleas spend part of their life cycle in the environment. Treatment includes protecting the dog against fleas, providing suitable protection for other animals in the home and reducing the number of parasites in the environment. [4]
Environmental allergies and atopic dermatitis
The term “inhalant allergy” was often used in the past because the mechanism was thought to resemble hay fever in people. In dogs, however, reactions to environmental allergens most commonly appear as itching and skin inflammation. Allergens may include:
• tree, grass and weed pollen,
• house dust mites,
• mould,
• other environmental factors.
Symptoms may be seasonal, for example becoming worse during pollen season, or may occur throughout the year. The paws, face, ears, armpits and abdomen are most commonly affected.
Atopic dermatitis is a chronic condition. It is usually impossible to remove every allergen from the dog’s environment completely, but symptoms and the frequency of flare-ups can be reduced. Treatment may include skin care, anti-itch medication, management of secondary infections and allergen-specific immunotherapy. [2]
Food allergies in dogs
A food allergy is an abnormal immune reaction to a dietary ingredient, most commonly a particular protein. Food should not, however, be assumed to be the cause of every skin problem. A food allergy may cause:
• itchy skin,
• paw licking,
• recurrent ear inflammation,
• redness,
• secondary bacterial or yeast infections,
• gastrointestinal problems.
Skin symptoms can look very similar to those caused by an environmental allergy. The location of the itching alone is usually not enough to establish whether food is responsible.
How is a food allergy diagnosed?
The most important method is a properly conducted elimination diet followed by a food challenge in which the previous diet is reintroduced. An elimination diet should be planned with a veterinary surgeon. It may use hydrolysed protein food or an appropriately selected novel protein source. During the trial, the dog should receive only the approved food. The result may be affected by:
• treats,
• table scraps,
• chews,
• flavoured supplements,
• flavoured medicines,
• food eaten accidentally.
An improvement after changing food is not enough to confirm an allergy conclusively. An important part of the diagnostic process is the return of symptoms after the previous diet has been reintroduced. Blood and saliva tests do not replace a properly conducted elimination and food-challenge trial. [5]
Contact allergies in dogs
Allergic contact dermatitis develops after direct contact with a substance that triggers a reaction. It should be distinguished from simple skin irritation, which can also occur without the involvement of the immune system. The problem may affect areas with less hair or parts of the body that come into contact with a surface or object, including:
• the abdomen,
• the groin,
• the armpits,
• the area around the muzzle,
• the spaces between the toes.
A potential factor may be a detergent, cosmetic, topical preparation, material or surface on which the dog lies regularly. The most important aspect of treatment is identifying and removing the factor causing the reaction. It is worth remembering, however, that contact dermatitis is neither the only nor the most common cause of changes appearing on the abdomen and paws.
What does allergy diagnosis in dogs involve?
There is no single simple test that answers the question: “What is my dog allergic to?” The diagnostic process may include:
- a detailed history of when the symptoms first appeared,
- examination of the skin, coat, paws and ears,
- checking protection against fleas and other parasites,
- skin or ear cytology,
- tests for parasites and infections,
- treatment of secondary infections,
- a controlled elimination diet,
- assessment of whether the symptoms are seasonal,
- additional tests depending on the individual case.
Intradermal testing or antibody testing may be helpful after atopic dermatitis has been diagnosed, primarily to select allergens for immunotherapy. A positive test result alone does not prove that a particular allergen is responsible for the symptoms. [2]
What can you give a dog for an allergy?
There is no single product suitable for every dog with an allergy. Management depends on whether the problem is:
• a flea allergy,
• an environmental allergy,
• a food reaction,
• contact with an irritating substance,
• a secondary skin infection,
• an acute allergic reaction.
A veterinary surgeon may recommend:
• medication to reduce itching and inflammation,
• antibacterial or antifungal treatment,
• antiparasitic products,
• topical treatment,
• bathing with an appropriate shampoo,
• an elimination diet,
• allergen-specific immunotherapy,
• treatment supporting the skin barrier.
Different groups of medicines are used in the treatment of allergic skin disease. These include oclacitinib, lokivetmab, glucocorticoids, ciclosporin and selected antihistamines. Each treatment has different uses, speed of action and contraindications. [6] Do not give your dog a random tablet simply because it is in the household medicine cabinet or helped another animal.
Can dogs take Zyrtec?
Zyrtec contains cetirizine, an antihistamine used primarily in people. Cetirizine is also sometimes used by veterinary surgeons in selected dogs. This does not mean, however, that Zyrtec can be given to every dog without professional advice. Before using it, a veterinary surgeon should consider:
• the dog’s body weight,
• their age,
• any existing medical conditions,
• kidney and liver function,
• medication already being taken,
• the severity and cause of the itching,
• the exact ingredients in the selected product.
Oral antihistamines are generally not the most effective way to manage a severe acute flare-up of atopic dermatitis. They may provide some benefit to certain dogs with milder itching or be used as part of a wider treatment plan. Their effectiveness is individual and often limited. [2][6]
Why does this article not provide a Zyrtec dose for dogs?
Veterinary medication doses should be selected for the individual patient rather than based solely on an approximate weight entered into a search engine. Relevant factors also include:
• the form and concentration of the medicine,
• the other ingredients in the product,
• how frequently it is administered,
• the dog’s overall health,
• the use of other medicines or supplements,
• the reason the medicine is being considered.
Using a dose found online may delay the correct diagnosis or cause an adverse reaction. Even if a veterinary surgeon previously recommended cetirizine for another dog, the same schedule should not automatically be used for a different animal.
Can Allertec be given to a dog?
Allertec also contains cetirizine. From the perspective of the active ingredient, the question about Allertec is therefore similar to the question about Zyrtec. It is still necessary to check:
• the exact product name,
• the amount of active ingredient,
• the form of the preparation,
• the full list of ingredients,
• the presence of any additional substances.
A product with a similar name may be available in different versions. Not every version will be suitable for a dog. A veterinary surgeon should decide whether it should be used and determine the dose.
Can chlorpheniramine be given to a dog?
Chlorpheniramine is another antihistamine that is sometimes used in veterinary medicine. As with cetirizine, its effectiveness can vary between individual dogs. It may also cause adverse effects such as drowsiness, agitation, gastrointestinal problems or other reactions depending on the patient. It should not be given without veterinary advice or based on a dose intended for people.
Can human allergy medicines be given to dogs?
Some substances used in human medicines are also used by veterinary surgeons. This does not mean that every human allergy product is safe for a dog. Combination products that also contain medicines for a blocked or runny nose can be particularly dangerous. Pseudoephedrine can cause:
• severe agitation,
• an increased heart rate,
• high blood pressure,
• muscle tremors,
• seizures,
• abnormal heart rhythms,
• life-threatening complications. [7]
Some syrups, drops, chewable products and liquid medicines may also contain xylitol. Xylitol is toxic to dogs and may cause a sudden fall in blood glucose, seizures and liver damage. [8]
Always check the entire ingredients list rather than only the main active ingredient. The safest approach is to consult a veterinary surgeon about the product name, manufacturer, form and concentration before giving the first dose.
Are there over-the-counter allergy medicines for dogs?
The fact that a medicine is available to people without a prescription does not mean that it can be used safely in a dog without professional advice. Itching may be caused by infection, parasites, a flea reaction, a food allergy or atopic dermatitis. Giving a random antihistamine may provide no relief and delay appropriate treatment. Some prescription veterinary treatments are considerably more effective for severe itching than traditional oral antihistamines.
Can calcium supplements be given to a dog for an allergy?
Calcium supplements are not a standard treatment for allergic skin disease in dogs. They should not be treated as a substitute for diagnosis or medication selected by a veterinary surgeon.
Giving calcium products without professional advice may be inappropriate, particularly if the dog has certain medical conditions, receives other supplements or eats a complete diet that already provides the correct amount of minerals. If your companion is scratching intensely, establishing the cause of the itching is far more important.
Home remedies for allergies in dogs – what can be done safely?
Home measures will not cure an allergy, but they may help reduce contact with some allergens and improve the dog’s everyday comfort.
After consulting a veterinary surgeon, you may:
• wash covers and blankets regularly,
• use fragrance-free laundry products,
• rinse fabrics thoroughly,
• vacuum the areas in which the dog rests,
• wipe or rinse the paws after walks during pollen season,
• use only a recommended shampoo,
• maintain regular parasite protection,
• keep a symptom diary,
• record changes in food, treats and cosmetics,
• prevent intense licking of damaged skin in accordance with veterinary advice.
Do not apply essential oils, human ointments, alcohol, vinegar or random cosmetics to your dog’s skin. Damaged skin may react with even greater irritation.
How can you relieve a dog’s itching before the appointment?
The safest first step is to contact the veterinary practice and describe the symptoms. The staff can help determine whether the dog needs an urgent appointment. Until the consultation:
• do not give human medicines without veterinary approval,
• do not change the food, shampoo and every accessory at the same time,
• reduce licking and scratching of the damaged area,
• check for swelling of the face or difficulty breathing,
• take photographs of the skin changes,
• write down when the symptoms first appeared,
• note any recently administered medicines, treats and parasite treatments.
Introducing many changes at the same time may later make it difficult to determine what genuinely helped or made the problem worse.
How should you care for the environment of a dog with allergies?
A dog spends many hours in direct contact with their own bed. Their resting place should therefore be cleaned regularly, kept suitably dry and free from strong detergent residues. When choosing a dog bed, it is worth looking for a removable and washable cover. Washing frequency and temperature should be adjusted to the manufacturer’s instructions and the veterinary surgeon’s advice.
Changing the bed alone should not, however, be expected to cure an allergy. It may be helpful when the veterinary surgeon suspects contact with a particular material or cleaning substance.
The same applies to a dog bowl. If the changes affect the muzzle or chin, the veterinary surgeon may recommend reviewing how the bowl is cleaned or changing the material. Bowl&Bone Republic offers dog bowls with different types of inserts, including ceramic and metal options.
The bowl should be washed thoroughly, its surface checked regularly and old food residue removed.
How long do allergy symptoms take to improve?
The time required for symptoms to improve depends on:
• the cause of the allergy,
• the severity of the itching,
• the presence of infection,
• the treatment being used,
• whether contact with the allergen can be reduced,
• the dog’s individual response.
Some anti-itch medicines may begin working relatively quickly. Repairing damaged skin and treating a secondary infection, however, require more time. In the case of an elimination diet, the results are usually assessed over many weeks rather than a few days. Even when symptoms improve, a properly conducted food challenge is required to confirm the connection with the diet. [5] Environmental allergies often require long-term management because completely avoiding pollen, mites or mould is usually impossible.
Can a dog recover from an allergy without treatment?
Symptoms may temporarily improve if the dog stops coming into contact with a particular factor. This does not mean, however, that the cause has been correctly identified or that the problem will not return. Atopic dermatitis is usually a chronic condition requiring long-term management. A food allergy also requires avoidance of the confirmed ingredient. Untreated itching may lead to skin damage, infection, pain, sleep problems and poorer everyday wellbeing.
Does a dog understand that they have an allergy?
A dog does not understand the concept of an allergy or the workings of the immune system. They do, however, experience itching, burning, pain and other symptoms. They may try to cope by:
• scratching,
• licking,
• biting the skin,
• rubbing against furniture,
• avoiding touch,
• frequently changing resting places,
• becoming restless.
The dog guardian and veterinary surgeon are responsible for identifying the problem and introducing suitable management. The dog’s behaviour can provide valuable information about the severity of the symptoms, but it cannot replace a veterinary examination.
Can a puppy have an allergy?
A puppy can also have an allergy or another condition that causes itching. In a young dog, however, it is particularly important to rule out parasites, infections, nutritional problems and irritation. Do not give a puppy medicines intended for adult dogs or people without professional advice. A young dog should be examined by a veterinary surgeon if they:
• scratch frequently,
• lose fur,
• have red skin,
• suffer from recurrent ear problems,
• have diarrhoea or vomiting,
• fail to gain weight appropriately.
Allergy treatment should be matched to the cause
Treatment should be supervised by a veterinary surgeon. Experimenting independently with diet or medication may delay the diagnosis and worsen the dog’s condition. Depending on the diagnosis, the plan may include:
• year-round flea protection,
• an elimination diet,
• reducing contact with a specific allergen,
• anti-itch medication,
• treatment of bacterial or yeast infections,
• medicated bathing,
• support for the skin barrier,
• allergen-specific immunotherapy,
• regular follow-up appointments.
When symptoms return, it is worth reassessing parasite protection, diet, seasonal changes and the presence of secondary skin or ear infections. [2][6]
Allergies in dogs require patience and a good plan
Many dogs suffer from allergic conditions. Management depends on the type of problem, the severity of the symptoms and the response of the individual patient.Sometimes the greatest improvement comes from effective flea control. In other cases, a strict elimination diet, treatment of an infection or long-term management of atopic dermatitis is required.
Always consult a veterinary surgeon. Acting without professional guidance can have the opposite effect to the one intended — particularly when a guardian gives a human medicine, changes many elements of the diet at once or applies substances that irritate the skin.
Living with a dog affected by allergies does not have to mean constant discomfort. Appropriate diagnosis, careful observation and consistent adherence to professional recommendations can bring considerable relief and allow your companion to return to peaceful sleep, walks and everyday play.
For more inspiration, knowledge and thoughtfully designed dog accessories, visit www.bowlandbone.com — a place created for dog guardians who wish to combine their companion’s everyday comfort with timeless style.
the Bowl&Bone Republic team
FAQ – the most frequently asked questions from the article “Allergies in dogs – symptoms, types and how to manage them”
What are the most common symptoms of allergies in dogs?
Common symptoms include itching, paw licking, red skin, hair loss and recurrent ear inflammation. Some dogs with a food reaction also develop gastrointestinal problems.
What can you give a dog for an allergy?
Do not give random medicines without consulting a professional first. A veterinary surgeon selects treatment according to the cause of the allergy, severity of the symptoms, the dog’s age, existing medical conditions and medicines already being taken.
Can dogs take Zyrtec?
Cetirizine, the active ingredient in Zyrtec, is sometimes used in veterinary medicine, but it is not appropriate for every dog. The exact product, ingredients and dose should be discussed with a veterinary surgeon before use.
What is the correct Zyrtec dose for a dog?
The dose should be determined by a veterinary surgeon. Choosing it solely on the basis of body weight and information found online does not take account of the dog’s health, other medicines or the product’s full ingredients.
Can Allertec be given to a dog?
Allertec contains cetirizine, but it should not be given without veterinary approval. The exact version, concentration, form and other ingredients need to be checked.
Is chlorpheniramine safe for dogs?
Chlorpheniramine is sometimes used by veterinary surgeons, but it may cause adverse effects and is not appropriate for every patient. Human doses should not be used independently in dogs.
Can dogs take human allergy tablets?
Not without professional advice. Some combination products contain pseudoephedrine or other substances that are dangerous to dogs. Liquid and chewable medicines may contain toxic xylitol.
Can calcium supplements be given to a dog for an allergy?
Calcium supplements are not a standard treatment for allergies in dogs. They do not replace diagnosis or treatment selected by a veterinary surgeon.
What home remedies can help a dog with allergies?
You can clean the resting area regularly, wash covers using fragrance-free products, rinse the paws after walks and keep a symptom diary. Essential oils, human ointments and medicines should not be used without veterinary approval.
How is a food allergy diagnosed in dogs?
The most reliable method is a strict elimination diet followed by a controlled reintroduction of the previous food. The process should be supervised by a veterinary surgeon.
Can a blood test confirm a food allergy?
Blood tests do not replace an elimination and food-challenge trial. Allergy testing is more useful when selecting immunotherapy for a diagnosed environmental allergy.
Why does a dog lick their paws?
Paw licking may result from an allergy, infection, parasites, irritation, a foreign body, pain or another problem. Recurrent or intense licking requires professional advice.
How long do allergy symptoms take to improve?
This depends on the cause and treatment. Itching may improve relatively quickly after suitable medication, but treating the skin, ears and infections may take longer. Elimination diets are assessed over many weeks.
Can a dog’s allergy disappear on its own?
Symptoms may temporarily improve when contact with an allergen ends, but allergic skin diseases often require long-term management.
Are allergies in dogs contagious?
The allergy itself is not contagious. Some conditions causing similar itching, such as certain parasites or infections, may nevertheless require additional precautions.
When does an allergic reaction require immediate help?
Urgent help is required if a dog develops sudden swelling of the face, difficulty breathing, severe weakness, pale gums, loss of consciousness, seizures or signs of shock.
Sources and inspiration used to create the article
“Allergies in dogs – symptoms, types and how to manage them”
- Merck Veterinary Manual, “Disorders Involving Anaphylactic Reactions”. A resource concerning the symptoms of anaphylaxis in dogs and the need for immediate veterinary treatment.
- Merck Veterinary Manual, “Atopic Dermatitis in Dogs”. A resource concerning the causes, symptoms, diagnosis and long-term management of atopic dermatitis in dogs.
- American Animal Hospital Association, “2023 AAHA Management of Allergic Skin Diseases in Dogs and Cats Guidelines”. Guidelines presenting a systematic approach to diagnosing and managing allergic skin diseases in dogs and cats.
- Merck Veterinary Manual, “Flea Allergy Dermatitis in Dogs and Cats”. A resource concerning hypersensitivity to flea saliva, typical symptoms and the importance of protecting both the animal and the environment against parasites.
- Merck Veterinary Manual, “Cutaneous Food Allergy in Animals” and AAHA, “Assessing Diet Trial Results”. Sources concerning the symptoms of food allergy and diagnosis using an elimination diet followed by a controlled food challenge.
- AAHA, “Acute Flare and Long-term Management Therapies in Dogs” and AAHA, “Oral Antihistamine Doses for Dogs”. Resources concerning the possibilities and limitations of anti-itch treatments, including antihistamines used in veterinary medicine.
- Merck Veterinary Manual, “Toxicoses in Animals From Human Cold and Allergy Medications”. A resource concerning the risks of giving animals products intended for people, including combination medicines containing decongestants.
- Merck Veterinary Manual, “Xylitol Toxicosis in Dogs” and U.S. Food and Drug Administration, “Paws Off Xylitol; It’s Dangerous for Dogs”. Resources concerning the toxicity of xylitol, which may be found in some syrups, chewable medicines and other products intended for people.
This article is educational in nature and provides general information about allergies and itching in dogs. It is not a substitute for an examination, diagnosis or treatment plan prepared by a veterinary surgeon.
