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Genetics: English Cocker Spaniels- Immune-Mediated Hemolytic Anemia (IMHA)

Identifying the gene mutations responsible for the development of IMHA in English Cocker Spaniels.

Dr. Steven Friedenberg and the Veterinary Genetics Laboratory at North Carolina State University College of Veterinary Medicine are working to identify the gene mutations responsible for the development of IMHA in English Cocker Spaniels. Our goal is to use this research to develop a test to help breeders decrease the frequency of the disease. We are also interested in using the results of our research to help predict disease severity and response to therapy.

We are seeking participants for this study

Requirements to participate are as follows:

  • Dogs of any age that have been diagnosed with immune-mediated hemolytic anemia, currently or in the past.
  • Your willingness to volunteer a blood sample from your dog for genetic testing

Please contact Dr. Friedenberg (or ask your veterinarian to contact him) to ensure that your dog is a candidate for the study. 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. 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 IMHA 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 DNA samples from English Cocker Spaniels that you are currently treating or have treated in the past for primary IMHA.

Inclusion and exclusion criteria for the study are as follows:

Inclusion criteria

  • CBC documenting HCT < 30%
  • Positive results on one of the following tests:
  • Slide autoagglutination test (macro or micro)
  • Pathologist-reviewed blood smear documenting spherocytosis
  • Coombs test with a titer of 1:64 or greater
  • Flow cytometry documenting erythrocyte surface-bound IgG or IgM

Exclusion criteria

  • Thoracic radiographs showing evidence of disease or foreign metallic objects at the time of diagnosis
  • Abdominal radiographs showing evidence of disease or foreign metallic objects at the time of diagnosis
  • Abdominal ultrasound showing evidence of disease at the time of diagnosis
  • Evidence of true infection with any erythrocyte-borne pathogen or rickettsial disease based upon blood smear, culture, convalescent IFA, or PCR

At a minimum, patients must have met both inclusion criteria concurrently. It is not necessary to have evaluated patients for all of the exclusion criteria. However, if you did perform any of the tests listed and your patient met one or more of the exclusion criteria, unfortunately we cannot include that patient in our study.

If you have any clients meeting the above criteria who may be interested in donating a blood sample for genetic testing, please e-mail Dr. Steven Friedenberg to discuss the case. If your patient qualifies, we will send you (or your client) a mailer containing a blood tube for DNA collection, a client consent form (can also be downloaded here), and a pre-paid return envelope. You can also use any standard EDTA tube (purple top) that you have in your clinic to collect the blood, (please fill the tube completely.)

We ask that you send any relevant medical records and the dog’s pedigree (if the client has it available) in the return mailer. You can also submit these papers electronically via e-mail.

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

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