Degenerative joint disease in the vertebral column in the cat: spondylosis deformans and osteoarthritis of the facet articulations

Abstract

Degenerative joint disease of the vertebral column can be divided in two types of degeneration. First there is degeneration of the intervertebral joints resulting in osteophyte formation, named spondylosis deformans. Second there is degeneration of the synovial facet articulations between vertebrae, named osteoarthritis. There are a few reports of spondylosis deformans in cats, but no reports of osteoarthritis of the facet articulations of the vertebral column. This literature review describes what is currently known about these two conditions considering prevalence, pathogenesis, clinical symptoms, diagnostic possibilities, radiographic symptoms and therapeutical options. Evaluation of the prevalence of osteoarthritis in the facet articulations of the vertebral column and spondylosis deformans of the vertebral column on radiographs from the archives of the Division of Diagnostic Imaging of the University Clinic for Companion Animals in Utrecht was performed. In total, 471 radiographs were evaluated for facet arthritis and spondylosis deformans. For each case the age, breed, weight, gender and disease for which the cat was presented were assessed. This research was done to learn more about risk factors and prevalence of facet osteoarthritis and spondylosis deformans in cats referred to the university clinic in the Netherlands. Frequency tables were made of all assessed variables. Logistic regression was performed per intervertebral space to evaluate putative risk factors (i.e. breed, gender, age, weight, trauma and diagnosis) in the development of spondylosis deformans in cats. Also prevalence of spondylosis per intervertebral space was calculated. Spondylosis deformans was related to age in most intervertebral spaces. An older cat has increased odds for having spondylosis than a younger cat. Spondylosis at two intervertebral spaces was related to gender. A female neutered cat has higher odds of developing spondylosis, compared to a male neutered cat. Spondylosis at one intervertebral space was related to weight. Occurrence of spondylosis was not related to disease and breed. Least spondylosis was found in the cervical region of the spine, and somewhat more was found in the lumbar region of the spine. Most spondylosis was found in the thoracic region of the spine with a peak incidence between Th5-Th10. Most bridges were seen in the late-thoracic and early-lumbar part (Th10-L2) of the spine. Early-to-middle thoracic region (Th1-Th10) was most frequently affected by small spurs and tooth-like shapes. Of the 471 evaluated radiographs, only six cats were found positive for facet osteoarthritis over some intervertebral spaces.