Characteristics of and risk factors for intervertebral disk extrusions in Pekingese

OBJECTIVE To characterize and identify risk factors for intervertebral disk extrusion (IVDE) in Pekingese. DESIGN Retrospective case-control study. ANIMALS 426 Pekingese (81 with confirmed IVDE and 345 without IVDE) admitted to a veterinary teaching hospital from 2005 through 2015. PROCEDURES Medical records were reviewed and data were extracted regarding age, sex, body weight, body condition score, coat color, chief reason for initial evaluation, body system involved, and diagnosis. Survey radiographs of the vertebral column were examined. Data were compared between the confirmed IVDE and non-IVDE groups. RESULTS Confirmed IVDE was uncommon in dogs < 2 years of age (2/81 [2%]). The extrusion was primarily located in the thoracolumbar (n = 57 [70%]) and cervical (22 [27%]) regions; the most common sites were T12-13 and C6-7. The number of radiographically visible calcified disks was significantly greater in the confirmed IVDE versus non-IVDE group, and the presence of calcified disks in the T10-L4 region was associated with increased odds of IVDE (OR, 21.2). Black coat color was significantly more prevalent in the confirmed IVDE versus non-IVDE group and was associated with increased odds of developing IVDE (OR, 1.6). Mean body weight and the proportion of spayed female dogs were significantly greater in the confirmed IVDE versus non-IVDE group. CONCLUSIONS AND CLINICAL RELEVANCE Several risk factors for confirmed IVDE in Pekingese were identified that could be useful for counseling clients about the disease or, with additional research, designing selective breeding programs to reduce the prevalence of IVDE in the breed.