Atopic Dermatitis in the West Highland White Terrier
A seminar presented by:
Dr. Thierry Olivry DrVet, PHD, DipACVD, DipECVD
Sponsored by: Westie Foundation of America, October, 2003
Summarized by: Donna Hegstrom, W.H.W.T.C.A. Health Chairperson
Reviewed By: Dr. Kay McGuire DVM., Member W.H.W.T.C.A. Health Committee
Winter 2004, NEWS
A seminar by Dr. Thierry Olivry on Atopic Dermatitis provided breeders, exhibitors and pet owners with the latest research information on the number one health issue affecting many West Highland White Terriers. According to the ACVD Task Force on Canine Atopic Dermatitis, Atopic Dermatitis is "a genetically-predisposed inflammatory and pruritic allergic skin disease with characteristic clinical features. It is associated most commonly with IgE antibodies to environmental allergens." With a high prevalence of breed predisposition, the age of onset in the westie is usually 6 months to three years of age. In diagnosis, it is important to consider the history of the breed, as well as the clinical signs, while eliminating diseases that look like Atopic Dermatitis. Clinical signs include chronic itching, skin lesions, licking of feet and the absence of hair in affected areas, as well as recurrent infections on the skin and ears and seasonality related outbreaks.
According to Dr. Olivry, it is important to eliminate any other clinical conditions such as scabies, fleas and other mite and insect infestations, food allergies, allergic contact dermatitis and bacterial and Malassezia (yeast) infections, prior to concluding a diagnosis of Atopic Dermatitis. It is important to control allergies and infections, such as those listed above, which often do co-exist with skin disease. In doing so, the diagnosis of Atopic Dermatitis can be made, having ruled-out or controlled the co-existing pruritic (itching) diseases.
Managing Atopic Dermatitis is extremely difficult and focusing on the use of medication alone only masks many of the symptoms. Management of the disease begins with the avoidance of known allergens such as fleas, molds and mites and the elimination of food allergies through diet trials. Changes of diet for a duration of 6-10 weeks, utilizing home-cooked or commercial formulas, and recording positive or negative results in combination with oral supplements such as Omega 6 fatty acids and nutritional supplements is important. Based on results, the elimination of food allergies by a change in diet, along with added supplements and topical formulations will often act as barriers to the disease. In addition immunotherapy may be considered if the dog responds poorly to antipruritic drugs. Intradermal testing and/or serum allergen-specific IgE testing is necessary for immunotherapy and can be time consuming and very expensive.
The use of pharmacotherapy in the treatment of Atopic Dermatitis in conjunction with the above management techniques has been studied and the results of use of oral glucocorticoids such as prednisone or oral cyclosporine has been good. The results of new research presented by Dr. Olivry, suggests that while glucocorticoids such as prednisone when used for short periods of time, do inhibit inflammatory cell activation, the side affects on the dog often included digestive upsets and skin infections and does not provide long term relief. The use of cyclosporine in canines resulted in the inhibition of the function of the cells that initiate immune reactions such as itching and skin disease as well as inhibiting the functions of effector cells of the allergic response. The results of cyclosporine therapy appear to show less side affects with longer relief. A new product with cyclosporine as a base is due to be released early next year and presented to the veterinary community at convention. The studies by the North Carolina State University Allergy Group has been made possible by funding provided by many groups including the AKC Canine Health Foundation and the Westie Foundation of America. The use of cyclosporine in the treatment of Atopic Dermatitis shows great promise, but additional studies are needed and will be conducted. Slides were presented of before and after treatments with positive results.
Dr. Olivry concluded our seminar with the following four important points:
- The treatment of canine Atopic Dermatitis is multi-facetted
- The Primary Goal is to identify and eliminate all flare factors such as bacteria, yeast and allergens.
- The Secondary Goal is to decrease clinical signs with pharmacotherapy.
- The Tertiary Goal is to prevent relapses with immunotherapy and allergen avoidance.