Degenerative joint disease (DJD) is a term that loosely encompasses various arthropathies, including:
- Osteoarthritis (OA)-disease of synovial joints characterized by loss of articular cartilage, osteophyte formation, bone remodeling, and inflammation
- Spondylosis deformans-disease involving fibrocartilagenous intervertebral joints of the spine characterized by development of bony spurs.
For the purposes of this article, both forms will be considered together.
Systems. Musculoskeletal, focusing on inflammation within joints and surrounding soft tissues. Bony changes are part of the cause and effect.
Genetic Implications. Some breeds of cat are at greater risk for hip dysplasia (eg, Maine coon) or patellar abnormalities (eg, Abyssinian), but breed predisposition for osteoarthritis has not been thoroughly studied.
Incidence/Prevalence. DJD and/or OA are extremely common in cats, increasing in frequency with age. Hardie, et al reviewed 100 radiographs of cats (older than 12 years) taken as part of diagnostic workups for multiple reasons and found that 90% had evidence of DJD.1 Godfrey performed a retrospective radiographic study on cats of all ages and found radiographic changes suggestive of OA in 22% of cats, with 33% of those showing clinical signs.2 In a third study (Clarke, et al) the prevalence of radiographic signs of DJD or OA in 218 cats was 33.9%, with 16.5% (mostly cats older than 10 years) exhibiting clinical signs.3
Geographic Distribution. Worldwide