Evidence of genetic contribution to patellar luxation in Toy Poodle puppies

Abstract

Patellar luxation (PL) is one of the most common orthopedic disorders in dogs and a genetic factor is considered to play an important role in the development of PL. Genomic analysis has attempted to identify the genetic markers associated with the development of PL but only suggestive markers have been identified. Carefully selecting breeds with higher incidence rates of congenital PL as well as affected dogs with more severe symptoms are required, but such information remains limited to date. This study aimed to assess the genetic contribution to the development of PL in puppies. Using data on PL from 2,048 puppies of the nine common breeds in Japan, the association of PL grades between the limbs, breed, and sex as well as the concordance of PL between littermates were examined. A significant correlation was found between right and left limbs in PL grades in all the puppies (Spearman rank correlation coefficient (r s )=0.91, P <0.001) and for each breed (r s =0.81–0.93, P <0.001). In total, 20.3% of the puppies were affected. The inter-breed difference in PL prevalence was 2.1–38.1%, and Toy Poodles showed the highest prevalence rates. Littermates of the affected puppies with PL grade ≥2 had a 16.2-fold higher risk ( P <0.001). Thus, these results suggest that PL in puppies is primarily influenced by genetics, especially in Toy Poodles. These data highlight the necessity of using a breeding scheme to decrease the prevalence of PL.

Medial Shoulder Instability: Prevalence and Treatment Outcomes in 17 Poodles and 31 Dogs of Other Breeds

“…These factors have the potential to cause instability independently, though the possibility of an interplay between the two exists, as seen with other polygenic, multifactorial traits in dogs such as hip dysplasia 28 and patellar luxation. 29 The absence of glenoid dysplasia shows that this is not the cause of MSI in our population, and hence, without note of other orthopaedic anatomical variations, suggests that an increase in soft tissue laxity is the likely explanation for the joint instability affecting these dogs. Whether or not this is due to an underlying hypermobility syndrome warrants further investigation.…”

Epidemiology of Cranial Cruciate Ligament Rupture and Patellar Luxation in Dogs from the Province of Buenos Aires, Argentina

“…9,17,19 Similarly, our retrospective data analysis did not support the role of sex as a risk factor for having cranial cruciate ligament rupture and patellar luxation, as already reported. 11,18,[20][21][22][23][24] Some authors found that female sex increased such risk 9,17,25 and others described more male dogs diagnosed with patellar luxation in their study populations. 6,20,25 Studies about the association between age and prevalence of cranial cruciate ligament rupture and patellar luxation have shown conflicting results.…”

The potential of translational research in dogs in human medicine

“…Furthermore, acquiring country-wise consistency in information may be required. For instance, breed-associated risks for developing canine lymphoma [37] and patellar luxation [38][39][40][41] differ among countries. Systematic genetic epidemiological research is possible, however it requires considerable efforts.…”