The effectiveness of genetic markers and the role of environmental factors in hip dysplasia and osteochondritis dissecans of the shoulder in German Shepherd, Labrador Retriever, and German Wirehaired Pointer (Deutsch Drahthaar) dogs

Abstract

Canine Hip Dysplasia (CHD) is the most frequently diagnosed orthopedic condition in dogs. Similar to CHD, osteochondritis dissecans (OCD) of the shoulder is a developmental disorder in dogs that significantly impacts animal welfare. As polygenic genetic disorders, they exhibit a complex mode of inheritance. Although there are numerous clinical studies, there is insufficient information about the genetic basis of these disorders. Therefore, this study aimed to assess the relationship of the prognostic genetic test markers with CHD and OCD in German Shepherd, Labrador Retriever, and German Wirehaired Pointer dogs. We evaluated the efficiency of five SNP markers from the prognostic genetic test for CHD (the Dysgen test) based on available GWAS data in German Shepherd, Labrador Retriever, and German Wirehaired Pointer dogs. Radiographs were captured and assessed according to the official FCI scale for hip dysplasia. In German Wirehaired Pointers, shoulder X-ray evaluations were also performed. We used custom FRET-based primer probes in Real-time PCR and Sanger sequencing for genotyping and tested the evaluation using multiple logistic regression procedures. German shepherds emerged as the most vulnerable to CHD (P < 0.001). In the final logistic model, females are expected to have a 3.54 times higher likelihood of experiencing CHD compared to males (P < 0.05). SNP BICF2G630558239 demonstrated a notable association with CHD, indicating that the GG genotype poses a risk. This SNP is situated in the intronic region of the KIF26B gene, a member of the kinesin superfamily implicated in evolutionarily conserved roles in embryogenesis. We did not observe any association between shoulder OCD-related arthrosis and the SNPs studied. These results may contribute to understanding CHD by identifying genotypes associated with epidemiological risk, prompting the need to conduct more thorough investigations.