Why Is My Dog So Itchy?
Coping with an itchy dog can be incredibly frustrating and can strain the bond between you and your pet. Persistent scratching, chewing, and licking can lead to infections and discomfort. This article aims to help you understand the most common causes of itching and allergies in dogs and provide guidance on managing these conditions.
What Are Allergies?
Allergies in dogs are complex conditions resulting from an overactive immune response to specific substances called allergens. These allergens can be proteins from plants, insects, animals, or foods. When a dog is exposed to an allergen, the immune system mistakenly identifies it as harmful and reacts defensively. Over time, repeated exposure leads to sensitization, causing exaggerated immune responses.
This reaction involves the production of antibodies that bind to mast cells. When an allergen interacts with these antibodies, mast cells release chemicals like histamines, causing inflammation. This inflammation leads to redness, swelling, and itching.
Are Allergies Inherited?
Some allergies in dogs are inherited. Atopic dermatitis (atopy) is a prime example, involving hypersensitivity to environmental substances like pollen. Dogs with a genetic predisposition to atopy typically start showing signs between one and three years of age.
Atopic dermatitis can occur in any breed of dog but there is an increased risk reported in Golden and Labrador retrievers, German shepherd dogs, bulldogs, boxers, pugs, Irish setters, Dalmatians, Scottish terriers, wirehair fox terriers, West Highland white terriers, Boston terriers, cairn terriers, Lhasa apsos, shih tzus and mini schnauzers.
What Are the Most Common Causes of Chronic Itching In Dogs?
Chronic itching in dogs can involve scratching, chewing, licking, and rubbing. The primary causes are external parasites and allergies. Examples of itchy external parasites include fleas and sarcoptic mange mites.
What Are the Major Types of Allergies in Dogs?
Allergies are a common cause of skin and ear conditions in dogs. Unlike humans, who often exhibit respiratory symptoms like watery eyes and sneezing, dogs with allergies usually show skin symptoms. The major types of allergies in dogs include:
Flea Allergy
Flea allergic dermatitis is the most common skin disease in dogs. Flea allergy is caused by the flea’s saliva, and it only takes a few bites to cause a problem. Dogs with flea allergies often scratch so much that adult fleas are hard to find. Fleas can survive year-round in warm climates or homes, making year-round flea treatment essential for reducing itch.
Food Allergy
Some dogs develop sensitivities to specific food ingredients such as proteins, carbohydrates, preservatives, or dyes. Diagnosing food allergies involves conducting a food trial with a hypoallergenic diet. If symptoms improve and then return when the former diet is reintroduced, a food allergy is confirmed.
Atopic Dermatitis
Atopic dermatitis is an allergy where skin or ear inflammation occurs in response to environmental allergens like plant pollens and house dust mites. Allergy tests help identify specific allergens, allowing for targeted immunotherapy to reduce sensitivity over time.
Contact Allergy
Contact allergies result from direct exposure to allergens such as flea collars, pesticides, grasses, and materials used in carpets or bedding. Symptoms include skin irritation and itching at the contact points, usually the feet and stomach.
What Are Common Allergy-Causing Substances (Allergens)?
Many substances can trigger allergies in dogs, including:
Pollens (from trees, grasses, and weeds)
Mold spores
Dust mites
Shed skin cells (similar to pet allergies in humans)
Insect proteins (such as flea saliva)
Certain medications
What Are the Symptoms of Allergies in Dogs?
Common symptoms of allergies in dogs include:
Itchy skin (localized or generalized)
Red, inflamed skin
Hair loss
Recurrent ear infections
Hot spots (areas of moist, red, and irritated skin)
Sneezing and coughing
Vomiting and diarrhea
Diagnosis and Treatment of Allergies in Dogs
Diagnosing allergies in dogs involves a thorough medical history and physical examination by a veterinarian. Tests that may be conducted include:
Intradermal skin testing: Injecting small amounts of potential allergens into the skin to observe reactions.
Blood tests: Detecting specific antibodies against allergens.
Elimination diets: Identifying food allergies by feeding a hypoallergenic diet and gradually reintroducing potential allergens.
Treatment plans are tailored to the type and severity of the allergy and may include:
Flea control: Using monthly preventatives and treating the environment to eliminate fleas.
Anti-inflammatory medications: Corticosteroids, antihistamines, and newer medications like oclacitinib (Apoquel®) and lokivetmab (Cytopoint®) can help reduce itching and inflammation.
Shampoo therapy: Regular bathing with hypoallergenic or medicated shampoos to soothe the skin and remove allergens.
Desensitization (immunotherapy): Administering gradually increasing doses of the allergen to build tolerance.
Nutritional therapy: Special diets formulated to reduce allergic reactions and improve skin health.
Secondary Infections
Allergies often cause recurring skin and ear infections. Bacterial and yeast infections, secondary to the allergy, can increase your dog’s itching. Long-term treatment with antibiotics and anti-yeast medications is commonly required, along with medicated bathing programs.
Can Allergies Be Cured?
Unfortunately, there is no cure for allergies, and they are usually lifelong. The goal is to control allergies and improve the quality of life for both you and your dog. Working with your veterinarian to diagnose the underlying cause of the allergy and itching may reduce the need for medications or enable your veterinarian to use more specific and targeted allergy treatments.
Home Care Tips for Managing Dog Allergies
As a pet owner, you can take several steps at home to help manage your dog's allergies:
Regular Bathing: Use hypoallergenic shampoos to remove allergens from the skin and coat.
Environmental Control: Reduce exposure to known allergens by keeping your home clean, using air purifiers, and avoiding certain plants or fabrics.
Flea Prevention: Maintain a strict flea control regimen using veterinarian-recommended products.
Diet Management: Follow your veterinarian's advice on hypoallergenic diets and avoid giving table scraps or unapproved treats.
Regular Veterinary Check-ups: Schedule regular visits to monitor your dog’s condition and adjust treatments as necessary.
Does Your Dog Have Allergies?
If you suspect your dog is suffering from allergies, consult with a veterinarian for an accurate diagnosis and effective treatment plan. Consider booking an online video consultation with one of our experienced veterinarians to discuss your pet's specific symptoms and get personalised advice on managing their allergies.
Medically reviewed by Dr. Kirra Balmanno