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Genetics: English Cocker Spaniels- Addison’s Disease

Identifying the gene mutations responsible for the development of Addison’s disease in English Cocker Spaniels.

Dr. Steven Friedenberg and the Veterinary Genetics Laboratory at North Carolina State University College of Veterinary Medicine Center for Comparative Medicine and Translation Research are working to identify the gene mutations responsible for the development of Addison’s disease in English Cocker Spaniels. Our goal is to use this research to develop a DNA test to help breeders decrease the frequency of this disease. We also hope to help human geneticists to better understand this disease in people.

We are seeking participants for this study

  • English Cocker Spaniels of any age that have already been diagnosed with Addison’s disease
  • English Cocker Spaniels greater than 10 years of age who do NOT have Addison’s Disease, with laboratory tests confirming the absence of the disease, and do NOT have a history of Immune Mediated Hemolytic Anemia
  • An AKC pedigree confirming that your dog is an English Cocker Spaniel is preferred, but not essential
  • Your willingness to volunteer a blood sample from your dog for DNA analysis

Unsure about whether your English Cocker Spaniel qualifies for the study? Please don’t hesitate to contact Dr. Friedenberg (or ask your veterinarian to contact them) at All information provided with the samples is strictly confidential.

How to participate in the study


Please contact Dr. Steven Friedenberg at if you are interested in having your dog donate a blood sample prior to contacting your regular veterinarian. Dr. Friedenberg will discuss with you whether your dog is a candidate for the study, and obtain the necessary medical records from either you or your dog’s regular veterinarian.

If your dog meets the criteria for the study, we will send your veterinarian a mailer that includes blood tubes, a consent form, and a postage-paid return envelope. You can then schedule a brief appointment for a blood draw with your veterinarian. After the visit, your veterinarian will send the blood and the consent form to us, along with any relevant medical records.

Please send a copy of your dog’s pedigree to with the blood sample (if you have it) as this will greatly assist us in our genetic studies. You can also e-mail it to Dr. Friedenberg directly at .


Thank you very much for helping us with our research in better understanding the genetic basis of Addison’s Disease in English Cocker Spaniels. If you have any clients who you think would be interested in participating in our study, or if your client has approached you about this study, the following information should be helpful.

We are soliciting samples from English Cocker Spaniels that meet the following criteria:

  • English Cocker Spaniels of any age, with typical electrolyte changes and ACTH stimulation test results that document the presence of Addison’s disease (typical hypoadrenocorticism)
    • The timing of the diagnosis is not important
    • Patients receiving medical therapy for Addison’s disease can be enrolled
  • English Cocker Spaniels of at least 10 years of age with either a basal cortisol concentration or an ACTH stimulation test result that rules out Addison’s disease, and also have no prior history of IMHA. The testing to rule out Addison’s disease must have been performed at > 10 years of age

We would particularly be grateful for any help you can provide with collecting samples from English Cocker Spaniels without Addison’s disease!

If you have any clients who meet either of the above criteria who may be interested in donating a blood sample for DNA analysis, please e-mail to receive pre-paid return shipping materials and an EDTA tube to collect blood for DNA. You can also use any standard EDTA (purple top) that you have in your clinic to collect the blood.

Because of the limitations we have in providing outside veterinary clinics with reimbursements, we can unfortunately not pay for ACTH stimulation tests performed at your clinic, however if you also ship serum to NCSU we can provide basal cortisol testing at no charge.

Please submit the following information to our laboratory, using the pre-paid shipping materials provided:

  • Blood drawn into a standard EDTA tube (purple top) with a minimum volume of 4 mL
  • Either (a) A copy of the laboratory results (from IDEXX, Antech, or any other diagnostic laboratory) documenting either the presence or absence of Addison’s disease as described above, OR (b) A 2 ml serum sample from English Cocker Spaniels > 10 years of age that have not been tested for Addison’s disease
  • A copy of the patient’s pedigree, if provided to you by the owner
  • A signed copy of the client consent form.

If you have any questions whatsoever about this study, please do not hesitate to contact Dr. Steven Friedenberg at for more information.

Thank you very much for your assistance with this effort. We genuinely appreciate your participation in our research


If you are interested in learning more about Addison’s Disease in dogs, here are some reliable sources: