Atopy in dogs
Atopy is one of the most common type of allergy in dogs. Between 3% and 15% of dogs suffer from an atopic condition1. Atopy is hereditary and it can lead to allergies against the pollen of some plants (e.g. grasses, weeds, trees), fungi or various dust and storage mites. Certain breeds appear to be at higher than average risk of developing atopy. Such breeds include the Lhasa Apso, Schnauzer, Alsatian, Boxer, Labrador, Golden Retriever, Poodle, West Highland White Terrier, Cairn Terrier, Jack Russell and Fox Terrier2.
The symptoms of an atopic individual usually manifest themselves before the age of 3 years. The initial symptoms are often mild and are tolerated by owners because they respond well to short-term symptomatic therapy or because they initially only appear at certain times of the year such as pollen allergies in the summer.
Pruritus without visible skin disorders is the most significant symptom in dogs. This manifests itself in frequent licking or biting of the paws and the rubbing of the head along the floor or other objects. Despite the frequent itching visible clinical symptoms to the head or extremities are observed in 60-70% of the patients. Recurrent ear infections can also be caused by an atopy (in over 75% of the cases1).
Sneezing, a discolouration of the fur (from licking) and/or bilateral eye infection are also observed in some patients.
Depending on the duration and the severity of the disorder, the lesions can vary between erythema (redness) to hyperkeratosis (keratinization) and/or lichenification (thickening) of the skin. In addition, other parts of the skin may also show clinical symptoms.
Atopy is often accompanied by seborrrhoea sicca (dry form of excess sebaceous excudate) mixed with skin flakes and superficial pyoderma (skin inflammation) due to bacterial (Staphylococcus aureus or intermedius) or yeast (Mallazesia) infection. When patients are being treated for an atopic dermatitis, they should also be treated for secondary symptoms (e.g. seborrhoea and/or pyoderma).
1 Hillier, et al. Vet. Immunol. Path. 81 (2001) 147-151
2 Sousa, et al. Vet Immunol. Path. 81 (2001) 153-157