Allergy tests

Let’s talk about allergy tests

Allergy is a genetically predisposed condition of hypersensitivity to substances that are common and harmless to most animals. The immunological mechanisms underlying allergy in dogs, cats and horses are essentially the same as in humans. There are five main types of allergy:

Atopy or atopic dermatitis Hypersensitivity to pollen, mites, moulds and dander
Food allergy: Hypersensitivity to protein components of the diet, such as chicken
Insect and flea allergy: Hypersensitivity to insect and flea saliva
Contact allergy: Hypersensitivity to materials such as plastic, linoleum and paint
Drug allergy: Hypersensitivity to antibiotics, antiparasitic and other medicines

Clinical Symtoms

Pruritus is an essential feature of allergy – its diagnosis therefore requires a history of itching. Cutaneous lesions such as erythema, excoriations and self-induced alopecia also relate to the severity of the disease.

Respiratory symptoms (allergic rhinitis, asthma), gastrointestinal symptoms (vomiting, diarrhoea, gastritis) and ocular symptoms (conjunctivitis) may also appear.

Reduced quality of life – for both pets and owners – is an outcome that has an impact not only on the health and wellbeing of the pet, but also on the human–animal bond.

Pathogenesis

Hypersensitivity is caused by a dysfunction in the animal’s immune system whereby the immune system incorrectly perceives a harmless substance as harmful. When an animal is in contact (physically or through inhalation or ingestion) with an allergen for the first time, its immune system will react by producing IgE antibodies.

These antibodies are specific for a particular allergen. When the animal encounters the allergen again, the allergen will be presented to a mast cell which is already connected to allergen-specific IgE. This leads to the production and release of undesirable inflammatory mediators such as histamine and cytokines.

How does the Allergy threshold work?

The diagram illustrates how your pet might reach their allergy threshold: How quickly this threshold is reached will vary between different animals. For some, one single allergen, perhaps exposure to dandelions or dust mites, may be enough to push that particular pet over its threshold. For another pet, it may be the cumulative effect of multiple allergens that results in symptoms occurring. Animals with allergies will always be more prone to flare-ups, as they will be closer to the threshold than animals without them.