A fawn French Bulldog sleeping on a tiled floor with a light blue mask. The dog is lying on its side with its head on the floor. The background has a white planter and a white table leg. The image is in natural light.

An allergy in dogs is an exaggerated immune system response to certain substances known as allergens. These allergens are proteins found in plants, insects, animals, or food. 

Dog allergies can cause various health issues and discomfort for your furry companion. Understanding allergies in dogs is crucial for providing them with the best care and relief. When a dog is repeatedly exposed to an allergen over months or years, the immune system becomes sensitised. Subsequent exposure to the same or related allergen triggers an excessive immune response. 

A close-up of a dog’s nose and mouth on a wooden floor. The dog has a light brown and white fur, a pink nose with black spots, and a pink tongue. The dog looks like it is sleeping or resting.

Normally, the immune system defends the dog against infections, but with allergies, this response can become harmful.

The immune reactions involved in allergies are intricate. They often involve allergen proteins binding to antibodies in the blood, which then attach to mast cells found throughout the body. 

When these antigens and antibodies interact with mast cells, they release potent chemicals, including histamines. These chemicals lead to local inflammation, causing symptoms such as redness, swelling, and itching, which are typical of an allergic reaction. Identifying common dog allergies can help you take preventive measures and recognising canine allergy symptoms early will lead to more effective treatment.

Knowing the triggers for dog allergies can help you create an allergy-friendly environment.

Common Questions About Dog Allergies

An infographic of a beagle dog with text about common allergy symptoms. The infographic has a white background and black and orange text. The dog is sitting and facing to the right. The text is divided into four sections: Ears, Face, Haircoat, and Feet. The text in the Ears section says “Inflamed, itchy, sometimes waxy”. The text in the Face section says “Rough, excessive hair loss around the eyes. Eyes may be red and watery”. The text in the Haircoat section says “Rough, discolored hair, excessive shedding of hair”. The text in the Feet section says “Inflamed, itchy, excessive licking”.
  • Symptoms: 

The most common sign of allergies in dogs is itchy skin, which can be localised or affect the entire body. Some dogs may also experience digestive issues like vomiting and diarrhea.

  • Prevalence: 

Allergies are unfortunately widespread among dogs of all breeds and backgrounds. Most allergies become apparent after six months of age, with many affected dogs being one or two years old.

  • Inherited Allergies: 

Certain allergies, such as atopic dermatitis (also known as atopy), are believed to have a genetic component. Atopy refers to allergies to environmental substances like pollens.

  • Allergen Types: 

A wide range of substances can act as allergens in dogs, including insect, plant, and animal proteins, as well as chemical molecules. Common allergens include pollens, mold spores, dust mites, and certain medications.

Types of Allergies 

Allergies can be classified based on the allergen itself, the route of exposure, the timing of the immune reaction, the affected areas of the body, and whether they are inherited.

A person cleaning a dog’s wound with a cloth in a room. The dog is a light tan large breed and the wound is a red scrape or cut on its back. The room has a purple object in the background.

Flea Allergy and Insect Bite Allergy:

Flea allergy dermatitis (FAD) is a common allergic reaction in dogs, primarily triggered by flea saliva. Even a single flea bite can cause severe itching in dogs with FAD. Strict flea control is crucial in managing this condition, often involving monthly preventatives and home treatments. 

In cases of severe itching, your veterinarian may prescribe antihistamines or corticosteroids to alleviate the allergic response. Antibiotics may be necessary if a secondary bacterial infection develops.

Atopic Dermatitis (Atopy):

Atopic dermatitis, often called atopy, is an allergic reaction to environmental allergens like tree pollens, grass pollens, weed pollens, moulds, mildew, and house dust mites. 

Itchy skin is a common symptom, and affected dogs may scratch, lick their feet, and exhibit other signs of discomfort. 

Treatment options include anti-inflammatory drugs, hypoallergenic shampoos, hyposensitisation therapy (allergy shots), and specialised diets.

A small golden dog with a blue collar eating from a black bowl with “Woof” on it. The dog is sitting on a wooden floor with a white wall behind it. The dog has a fluffy golden fur, a blue collar with white bones, and a black nose. The dog is looking at the bowl and enjoying its food. The bowl is black with white letters that say “Woof”. It is filled with dog food.

Food Allergy:

Food allergies in dogs can develop in response to specific protein or carbohydrate components in a dog's diet. Common allergens include beef, chicken, lamb, eggs, dairy products, and soy. 

Identifying the offending components and eliminating them from the diet is crucial. Veterinary hypoallergenic diets and careful monitoring can help diagnose and manage food allergies.

Contact Allergy:

Contact allergies in dogs, also dog skin allergies, result from direct exposure to allergens, such as pesticides, grasses, or materials used in carpets or bedding. These allergies are less common but can lead to skin irritation and itching at the points of contact. Identifying and removing the allergen can often resolve the issue. 

A pug dog relaxing on a beige couch with a gray cushion. The pug has a light brown fur with darker brown around its wrinkled face and a black nose. The pug is lying on its stomach with its head on its paws.

It's important to note that diagnosing allergies in dogs should be done by a veterinarian, as the symptoms can overlap with other conditions. A complete diagnostic evaluation is necessary to determine the cause of itching and skin problems in your pet. Following your veterinarian's guidance closely is essential to provide relief for your dog's discomfort. Proper pet allergy management can significantly improve your dog's quality of life.