Inhalant allergies

Our four-legged friends, as well as humans, may be subject to allergies due to inhalation of specific allergens that are inhaled and cause chronic itchy forms, most frequently affecting dogs than cats. The disease, known as atopic dermatitis, affects mainly the skin, although rhinitis and asthma may also occur in some cases. Dermatitis is often caused by the inhalation of allergens in the environment (pollen, mold, dander , food) to which animals were previously sensitized, having been absorbed through the skin and by the gastrointestinal tract.

A genetic predisposition among dogs is recognized, making the skin barrier more permeable to allergens which get thus in contact more easily with the immune system, by sensitizing the animal to substances commonly found in the environment, which in healthy individuals do not create any problems. The most affected breeds are: Shar-pei, Wirehaired Fox Terrier, Golden Retriever, West Highland White Terrier, Scottish Terrier and Labrador Retriever.

The allergic reaction follows a mechanism of type I hypersensitivity, in which are involved immunoglobulin type E (IgE), allergen-specific. When these IgE – fixed on the surface of specific immune cells (mast cells) – get in contact with the specific allergen, they cause – through the mast cells in the skin – the release of substances that cause inflammation and pruritus. Itching is the hallmark and the most affected areas are legs, snout, ears, underarms and abdomen. These areas are devoid of hair with excessive sweating. The lesions are due to the damage that animals inflict to themselves, by biting the extremities of their legs and their underarms because of the intense itching, and are worsen by the constant licking and scratching.

Generally, symptoms begin to manifest according to the season in early spring, continuing during the summer and getting better during the cold season. However, in order to correctly identify the inhalant allergy, a vet’s visit is essential to rule out other diseases such as food allergy, flea and contact allergies, as well as dermatitis caused by parasites, bacteria or fungi.

There are three kinds of treatments against allergy: the first is the identification and the elimination of the responsible allergen; the second is the administration of anti-inflammatory drugs and antihistamines to control symptoms; the third is the hyposensitizing immunotherapy, which aims to increase the ability of the animal to tolerate the exposure to the inhalant allergen without developing clinical signs.

Very often a multi-modal approach turns out to be more effective, based on the association of drug therapy with soothing emollient baths, to control secondary bacterial infections, and the nutritional therapy with essential fatty acids, which significantly reduce the doses of drugs needed for the pruritus management.