Study Start Date: 07/31/2007
Study End Date: 12/31/2008

Study of the genetics of osteochondrosis in the Great Dane

Osteochondrosis (OCD) most commonly affects rapidly growing, large and giant breed dogs, males more commonly than females. Animals are typically affected during the periods of rapid growth and the majority of animals, depending on which joint is involved, will exhibit clinical signs by the time they are 10 months of age. Less than 17% of cases will exhibit clinical signs associated with shoulder OCD after they are 12 months of age. Therefore, dogs can be phenotyped with reasonable certainty as affected with OCD based on clinical signs of lameness and radiographic signs consistent with OCD, and phenotyped as unaffected with OCD if they have no clinical signs of lameness after they are two years of age. In addition, the Great Dane is considered a high risk breed for development of OCD. This information, combined with the fact the specific breeds are considered at increased risk for OC while other breeds are considered protected from OCD (i.e. greyhound) suggests and underlying genetic basis to OCD in the Great Dane dog.

Our goal is to develop a database (pedigree, DNA, medical health information) of Great Danes affected with OCD or unaffected. Analysis of this pedigree will allow us to obtain a most likely mode of inheritance for OCD. Using DNA samples of animals represented in the pedigree we will then perform additional studies including a genome wide linkage mapping (genome scan) to search for genomic regions associated with the disorder and eventually target likely OCD genes. Then, using a combination of comparative gene maps between humans and the dog to identify positional candidate genes and previously identified biological candidate genes we will search for mutations associated with differences between normal and affected dogs. This mutation or mutations will then be tested for informativeness to the disease state, and if informative, will be used as a marker for the disease.

Study Design:
Prospective database formation

Sample Size:
200-400 dogs

Inclusion Criteria:
Clinically affected Great Dane with osteochondrosis (OCD) is defined based on radiographic evidence of OCD, with obvious lameness, or surgical confirmation of an OCD lesion.

Exclusion Criteria:
Dogs that are not Great Danes. Great Danes under 2 years of age that do not have an OCD lesion.

Documents to Download:
   Medical History Questionnaire
   Study Information
   Consent Form

Study Controls:
Great Dane greater than two years old and unaffected with OCD

Samples:
We are collecting the following materials from owners:
   1. Pedigree (Preferably three generations or more)
   2. DNA sample (Blood sample or buccal swab)
   3. Medical History Information (Please contact us to receive questionnaire)

Costs/Reimbursements:
The first 100 dogs that submit samples into the study will be reimbursed as follows: $50 for pedigree and blood sample; $25 for additional dog(s) with pedigree and blood sample; $25 for pedigree and buccal swab; $10 for additional dog(s) with pedigree and buccal swab.

Full Disclosure information:

• The study is funded by a grant from Waltham Foundation.
• The investigators do not have any conflict of interest.
• The study will be published if results are negative.
• The study will be reported on VIN.
• The authors will acknowledge VIN if the study is published.