Page 1002 - Veterinary Immunology, 10th Edition

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FIG. 30.6 A moist “hot spot” on a Golden Retriever. (Courtesy Dr. R.
Kennis.)

Genetic Background

The development of canine AD is determined in part by genetic
factors. While not highly heritable, disease occurrence differs
between breeds. AD is most common in West Highland White
Terriers, Labrador and Golden Retrievers, German Shepherds,
Cocker Spaniels, Boxers, French Bulldogs, and Shar-Peis. Both

susceptibility and protective gene loci have been identified in dogs.
Careful clinical evaluation has recognized several disease
phenotypes that differ in such features as age of onset, the presence

of hot spots, gastrointestinal disorders, flexural dermatitis, and the
distribution of the skin lesions. Some breeds may develop lesions in
specific areas. French Bulldogs develop lesions in the axillae,
eyelids, and flexural surfaces. German Shepherds, in contrast, tend
to develop lesions in the elbows, hind limbs, and thorax.

Environmental Influences

Extrinsic AD is commonly associated with reactions to
environmental allergens such as molds; and tree, weed, and grass
pollens (especially pollens that are small and light and are

produced in very large quantities); and as a result may be seasonal.
Nonseasonal AD is mainly associated with allergies to house dust

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