In Thailand, the prevalence of medial patellar luxation (MPL)
and lateral patellar luxation (LPL) in small-breed dogs is 87% and
13%, respectively (Wangdee et al., 2005). Pomeranians are currently
also the highest ranking breed for PL in the USA, with
42.4% of dogs affected.2 Defects in collagen formation underlie a
number of orthopaedic diseases in humans, and these disorders
are often caused by inherited mutations in genes encoding collagen
proteins (Salg et al., 2006). As collagen genes are suggested to be involved
in PL and hyperextension syndrome in dogs (Temwichitr
et al., 2007), we investigated the possible involvement of these
candidate genes in PL in Pomeranian dogs.