Tracking Our Progress...Addison's Disease

By Karen Lindberg

Summer 2004, NEWS

When the Westie Foundation of America, Inc., in collaboration with the WHWTCA, conducted a breed health study in 1999, Addison's Disease, which is difficult both to diagnose and to treat, placed near the very top of the list of concerns of breeders and owners. A grant proposal offered by a research team at the School of Veterinary Medicine at the University of California - Davis therefore received our support both in funding and in soliciting samples. That project is on target.

The goal of this research is to compare DNA samples of normal and affected dogs and determine the presence of Linked DNA markers, which might lead to better identification of Westie Addison's Disease. The process involves extracting DNA samples we submit. The researchers will analyze the data to determine if there is a single locus and then initiate screening to search for a genetic marker linked to that locus.

This extended ongoing project will not be completed until a statistically significant number of samples are collected. Two types of specimens are needed: Addison's affected dogs and unaffected, normal dogs. The owner submits a cheek swab and completes a questionnaire that specifically requests the name of sire and dam and asks that a pedigree be attached for use in the statistical part of the analysis. Westie owners who do not have a pedigree on their dogs can participate by submitting the cheek swab sample so the scientists can determine if it fits the protocol. All information is confidential and neither dogs nor owners will be named in the final reports.

We have had wonderful response to the request and have, to date, collected 271 samples, including 229 normal, 31 affected and 11 unknowns. The unknown category designates those kits that have been returned without the survey questionnaire being completed. At the current rate of 22 kits per month, we should be able to gather a final sampling within the next six months.

All research projects are complicated. Using Health Survey information, the Westie Foundation Board of Directors first prioritizes diseases for investigation. They then submit requests for specific disease research to the AKC Canine Health Foundation and the Morris Animal Foundation who then solicit grant proposals from veterinary research facilities across the country. Then, the Westie Foundation works with the CHF and Morris to determine which proposals are deemed worthy of funding for the research areas we requested. Once everyone agrees with the project and the funding, the grant research commences. Finally, the project is completed and results reported but rarely until the very end do we realize how many people and many hours are involved.

The Addison's project principle investigator is Anita M. Oberbauer, Ph.D. She is a professor in the Department of Animal Science at Davis and is in the Genetics and Molecular, Cellular, and Integrative Physiology Graduate Groups. Her research program has two areas of emphasis: growth regulation of the skeleton and the genetic basis for health disorders in dogs. Dr. Oberbauer teaches courses in companion animal biology which couples nicely with her hobby of showing Belgian Tervuren.

Part of the project is researcher Thomas Famula; a professor in the Department of Animal Science at Davis, he is a member of the Genetics and Biostatistics Graduate Groups. His research interests are quantitative genetic theory and statistics, with a particular emphasis in the genetic evaluation of disease and temperament in dogs. Dr. Famula teaches an introductory animal science course and courses in quantitative and population genetics. In a collaborative work such as this, the research area begins as a purely statistical problem that asks the question: Is this disorder inherited? Once inheritance is established, a search for the statistical evidence of the impact of single genes on this disease begins; this area of investigation is called 'complex segregation analysis.' The next phase of research is to combine pedigree and disease information with DNA markers and maps of the canine genome.

The Westie Addison project is in the first phase as the researchers are asking: Is Addison's in the Westie inherited? When information on a sufficient number of Westies has been obtained this question can be answered and then the next step can begin. It is NOW that YOU can be an important part of the research project. Go to www.westiefoundation.org and learn how you can obtain a sample kit; once that kit arrives, perform the simple cheek swab and submit it. It will cost you only a few minutes of time but it can mean so much to the Westie breed.