**Samoyed enrollment for this study is closed. SCARF wishes to thank the efforts of many Samoyed owners for contributing to this research study. **
Determination of Breed-Specific Reference Ranges for Assessing Thyroid Function in Several Breeds
Sponsor(s):
Alaskan Malamute Research Foundation, Inc., English Setter Association of America, Golden Retriever Foundation, Keeshond Club of America, Orthopedic Foundation for Animals, Samoyed Club of America Education & Research Foundation, Siberian Husky Club of America
**Researcher (s): **
Rebecca L. Davies, PhD
Sheila Torres, DVM, MS, PhD, DACVD
University of Minnesota Veterinary Diagnostic Laboratory
Project Summary from the AKCCHF.org website:
“The thyroid gland secretes hormones which are very important for development, growth, reproduction and metabolism. Sometimes the thyroid gland does not produce enough thyroid hormone and hypothyroidism occurs. Hypothyroidism is very common in dogs and many are treated with thyroid hormone supplementation. This disease occurs frequently in Alaskan Malamutes, English Setters, Golden Retrievers, Keeshonden, Samoyeds, and Siberian Huskies. Hypothyroidism is generally diagnosed by measuring the concentration of thyroid hormones in serum. This concentration is then compared to a reference interval derived from measurements of thyroid hormone concentration in samples taken from large groups of normal dogs. Generally this works very well, however, in some breeds, the true reference range is lower than the range determined when dogs of various breeds (or mixed-breeds) are analyzed. Breed-specific thyroid hormone reference intervals have only been determined in a few breeds. Without breed-specific intervals, inappropriate use of general values may result in healthy dogs being misclassified as hypothyroid. These animals may be incorrectly placed on thyroid supplementation, and unnecessarily removed from breeding programs. Furthermore, the incidence of hypothyroidism in the breed will be overestimated. We wish to establish breed-specific normal thyroid reference intervals to improve the diagnosis of true hypothyroidism in the Alaskan Malamute, English Setter, Golden Retriever, Keeshond, Samoyed, and Siberian Husky breeds.”
Update from the AKCCHF.org website:
“All dogs have completed the recruitment, enrollment and screening process. All samples from all dogs have been collected. Six hundred dogs were enrolled* and 77 dogs were rejected due to their failure to pass inclusion criteria. All analytical testing (health screening data and hormone analyses) has been completed. Preliminary data has been presented at the American College of Veterinary Internal Medicine meeting in Anaheim, CA in June 2010 where it was concluded that Basal serum T4 and FT4D concentration vary among breeds and use of breed-specific reference intervals is recommended when evaluating thyroid function in purebred dogs. The research team greatly appreciates the support of AKC, the CHF, the OFA and the AKC dog clubs and officers. Thank you for giving us this opportunity to carry out this work.”
* including 100 Samoyeds!
Publication:
Hegstad-Davies RL, Torres SMF, Sharkey LC, Gresch SC, Munoz-Zanzi CA, Davies PR (2015). Breed-specific reference intervals for assessing thyroid function in seven dog breeds. Journal of Veterinary Diagnostic Investigation. 27: 716-727.
Sharkey, L., K. Gjevre, R. Hegstad-Davies, S. Torres and C. Munoz-Zanzi (2009) Breed-associated variability in serum biochemical analytes in four large-breed dogs. Veterinary Clinical Pathology. 38, 375-380. “Breed- Specific Reference Intervals for Assessing Thyroid Function in Seven Dog Breeds.”
PARTICIPATION CRITERIA
Wanted
100 each of Keeshond, Malamute, and Samoyed dogs to participate in a study to establish breed-specific reference ranges for thyroid hormone levels. As of 10/31/08, 35 more normal Samoyed samples are needed.
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Healthy dogs only - Dogs with chronic health concerns should not be enrolled. Dogs previously diagnosed with thyroid problems or that show signs of thyroid problems (obesity, lethargy, poor hair coat, and infertility) are not eligible to participate. Please do not enroll animals that you suspect may have ‘thyroid issues’. The appropriate dogs are those that you are most convinced are healthy, fit, and robust animals.
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Between one and eight years of age
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Females should be non-pregnant, non- lactating and not in season
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Dogs can be on heartworm, nutritional supplements*, flea and tick medication but cannot be on other drugs. Dogs must be off any drug therapy (eye or ear drops, antibiotics, steroids etc) for at least 12 weeks prior to enrolling in the study. *Supplements are acceptable but please record their use on the health questionnaire.
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Animals must be fasted for at least 6 hours prior to sampling.
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AKC registered (or able to provide evidence of purebred status)
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More information below - note, dogs must be enrolled in the study before samples are submitted.
What We Need
In order to participate outside of the Minnesota metro area (free sampling clinics are available at the University of Minnesota for local dog owners) owners must arrange with their veterinarian for proper sample collection and physical exam of their dog.
Participating dogs will undergo a physical examination and your veterinarian will collect urine and blood (for a complete blood count, blood chemistry profile, urinalysis, and thyroid levels) samples for the study.
Dog owners must pay the fees associated with the physical exam and sample collection procedures which are reimbursable up to $100 by SCARF- click here.
Dr. Davies will pay for shipping the samples collected by your veterinarian to her laboratory for analysis.
Dogs will be screened for healthy attributes using the results of the physical exam and the initial blood tests (CBC, chemistry profile, and urinalysis). If data are consistent with a healthy status, the thyroid panel (T4, Free T4 by dialysis, TgAA and TSH) of tests will be determined. Results of all tests which are run (screening only, or screening + thyroid tests) will be reported to the owner. The University of Minnesota Endocrine Lab, directed by Dr. Davies, is an OFA approved laboratory. Therefore, owners may also choose to have the thyroid levels done and reported to OFA. OFA has graciously waived the thyroid registration fee. If the dog is not passed into the thyroid testing part of the study (due to abnormalities found during the initial screening), the owner may request having the thyroid levels run at the owner’s expense. Volunteers will receive comprehensive laboratory data at no charge to the owner. More importantly, you will have the pride in knowing that you have participated in an opportunity to improve the health management of your favorite breed
Samples that are received without going through the enrollment procedure cannot be analyzed.
To Participate
For more information or to enroll your pet in this study or if your regional club in the mid-west would like to plan a collection event, please contact Dr. Rebecca Davies at 612-626-0168 or rdavies@umn.edu or http://www.cvm.umn.edu/cic/current/endocrine/home.html
- Request a “Blood, Sweat and Cheers” information packet in order to participate in the Thyroid Research Project. The packet will contain:
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A health questionnaire that needs to be completely filled out and returned with the blood and urine samples.
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A client consent form which needs to be signed and returned with the study samples.
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A letter to your veterinarian which describes the study and requirements for the physical exam and sample collections.
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A frequently asked question form to provide additional information.
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Please include the breed, sex, date of birth of your dog and your complete contact details in your initial email. The names, address, phone number and email address of your veterinarian is also required.
- **Discuss the study and requirements with your veterinarian and schedule an appointment for a Monday, Tuesday or Wednesday **(to allow for over-night delivery to Minnesota laboratories prior to Friday). Once the appointment is made, notify Dr. Davies (rdavies@umn.edu or 612-626-0168) so that she can officially enroll your dog into the study. Dr. Davies will need to discuss the collection with your veterinarian by email prior to final enrollment and sample submission. Sample collection and shipping timing are critical to sample acceptance so it is important to have all three parties (owner, veterinarian and Dr. Davies) in communication regarding dog enrollment.
Samples that are received without going through the enrollment procedure cannot be analyzed.
This project is also supported by the American Kennel Club Canine Health Foundation and the Orthopedic Foundation for Animals.