Cause
I. The etiology is unknown; however, hypocellular cartilage
has been detected histologically in some affected dogs.
II. Abnormal chondrocyte function with defi cient production
of the matrix components may result in altered integrity
of the cartilage ring structure and a predisposition to
collapse.
III. An increased incidence of disease is seen in small-breed
dogs, such as the poodle, Yorkshire terrier, Pomeranian,
and Chihuahua.
A. Clinical signs are often seen at an early age, and it is
possible that this disorder is congenital.
B. Poor nutrition or metabolic infl uences may contribute
to a failure of chondrogenesis and the development of
abnormal cartilage metabolism in these breeds.