Cross-Sectional Study of the Prevalence of Radiographic Degenerative Joint Disease in Domesticated Cats

Objective To determine the prevalence of radiographic signs of degenerative joint disease (DJD) in a randomly selected sample of domestic cats. Study Design Prospective observational study. Animals Client-owned cats. Methods Cats (n=100) from a single practice and equally distributed across 4 age groups (0-5; 5-10; 10-15, and 15-20 years old) were randomly selected (regardless of heath status) and sedated for orthogonal radiographic projections of all joints and the spine. Quasi-Poisson regression analysis was used to investigate the relationship between patient demographics, blood biochemistry, hematologic and urine analysis variables, and DJD severity. Results Most (92%) cats had radiographic evidence of DJD; 91% had at least 1 site of appendicular DJD and 55% had >= 1 site of axial column DJD. Affected joints in descending order of frequency were hip, stifle, tarsus, and elbow. The thoracic segment of the spine was more frequently affected than the lumbosacral segment. Although many variables were significantly associated with DJD, when variables were combined, only the association between age and DJD was significant (P <.0001). For each 1-year increase in cat age, the expected total DJD score increases by an estimated 13.6% (95% confidence interval: 10.6%, 16.8%). Conclusion Radiographically visible DJD is very common in domesticated cats, even in young animals and is strongly associated with age. Clinical Relevance DJD is a common disease of domesticated cats that requires further investigation of its associated clinical signs.