Severe allergy symptoms in dogs can arise from atopic allergies (airborne), flea allergy, food allergies, or contact allergies. Initially the dog is exposed to the irritant, causing the immune system to produce antibodies to the allergen. A following exposure begins a reaction of the antibodies to the allergen and a release of histamine. As opposed to humans who experience upper respiratory symptoms with allergies, dogs experience allergic irritation in their skin.
The fur in a dog's coat can trap allergens close to the skin where they are ingested during grooming or absorbed directly into the skin. The pads of a dog's paws are also exposed to allergens on the ground that are easily absorbed.
Types of Allergies
Atopic allergies occur in response to inhaled or airborne allergens such as dust, pollens, molds and smoke. Pets may become more sensitive to airborne allergens with age and can experience symptoms from indoor and outdoor allergens. Contact allergies occur when the dogs skin comes in direct contact with an allergen such as carpet fibers, plastics or cleaning chemicals.
Flea allergies are a reaction to the saliva of the parasites and can often be easily treated and controlled once the infestation is gone. Food allergies, which often occur in dogs in conjunction with atopic allergies, can develop in response to any food that the dog has been exposed to one or more times.
Allergy Symptoms
Symptoms of allergies include
- Intense scratching
- Chewing at paws
- Constant grooming of sides and groin
- Rubbing or clawing at face
- Constant scratching of ears
- Red or inflamed ears
- Ear infections
- Hives or papules on skin
- Hair loss
- Pyoderma, or skin infections
- Runny nose
- Watery eyes
More severe allergic reactions can occur in some dogs in response to allergens. Drugs, chemicals, or insect bites can cause allergic reactions that are more severe and have a rapid onset of symptoms. Within 20 minutes of exposure the dog may display symptoms an allergic reaction that may lead to anaphylactic shock. Anaphylactic shock is an immediate reaction of severe hypersensitivity to an allergen that can result in collapse and death. If symptoms arise that indicate possible anaphylactic shock, veterinary care should be sought immediately.
Symptoms include:
- Hives
- Swelling of face and eyes
- Diarrhea
- Vomiting
- Weakness
- Labored breathing
Treatments of Allergy Symptoms
If possible, it is first recommended to remove the allergen from the dog's environment. In many situations, such as with airborne allergens, this may not be possible. The symptoms of the allergy can be controlled if the allergen cannot be removed.
To control the irritation and itching, antihistamines or corticosteroids may be administered. Corticosteroids have proven to be the most effective at controlling itching but they must be used in low doses for a short period of time. Topical and oral antibiotics will be prescribed if the irritation of the skin has caused pyoderma. Prescription strength shampoos can be obtained from a veterinarian to treat infected skin and rehydrate it. Essential fatty acid food supplements can also be administered to heal skin that is irritated from allergies. In cases of food allergies, a food-elimination trial may be recommended to determine the allergen .