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WBFSH Seminar - Lina Jönsson

17-11-2009

Lina Jönsson (Photo: Ridehesten.com).
Lina Jönsson (Photo: Ridehesten.com).
Prevalence and heritability of osteochondrosis (OC) and POF in SWB horses

"Results from a study on animal hospital data"


The objective of this study was to evaluate animal hospital data as a source of information for estimation of the prevalence and heritability of osteochondrosis (OC) and osseous fragments in the stifle, hock and fetlock, and of palmar/plantar osseous fragments (POF) in the fetlock. Data were obtained from Helsingborg animal hospital, south Sweden, for horses of all ages examined in years 1992 to 1998. Prevalence estimation was based on radiographic examinations of 879 normal horses, mostly screened as part of a pre-purchase examination, and 3639 horses with clinical symptoms. For the heritability study these two data sources were pooled, after verifying that they produced similar results, and 3199 examined horses with pedigree information contributed data to a linear animal model analysis. The prevalence of OC was 13% (stifle 9%, hock 6% and DOF 9%) and for POF 11%. The heritability of OC, independently of affected joint, was 0.05 on the visible binomial scale. The corresponding heritabilities for OC in the stifle were 0.03, in hock 0.08, for DOF 0.10 and for POF 0.13. These values correspond to heritabilities of 0.09-0.38 on the underlying quantitative scale. Previously, disease records from animal hospitals have not been extensively used for genetic studies, likely due to non-harmonized systems for reporting among different clinics, unavailability of the records, and a risk for selection of individuals. This study showed that disease data obtained from animal hospitals may be a valuable asset in studies of inherited disorders and possibly even for genetic evaluations. There is, however, a need for improvements in documentation of pedigrees and availability of the data.