The medical records and magnetic resonance images of 33 dogs with surgically confirmed Hansen type I cervical intervertebral disc disease were reviewed. Fourteen of the dogs were chondrodystrophic and 19 were not chondrodystrophic. The most common clinical sign was neck pain, which affected 28 of the dogs, and 23 of the dogs were able to walk. Fifteen of the dogs had developed clinical signs acutely, within the previous 24 hours. On cross‐sectional images the median area of spinal cord compression was 26 per cent (range 11 to 71 per cent) of the normal spinal cord area. The degree of spinal cord compression was significantly associated with the dogs' presurgical neurological status but not with their postsurgical neurological status. The dogs with an acute onset of clinical signs had more severe neurological dysfunction before surgery, but their condition improved more as a result of surgery.

Medical records of 92 cats presented with clinical signs of spinal cord disease, which had undergone magnetic resonance imaging (MRI), were reviewed. The cats were grouped into seven categories based upon the diagnosis suggested by results of MRI, cerebrospinal fluid analysis and other diagnostic procedures: neoplastic ( n=25), inflammatory or infectious ( n=13), traumatic ( n=8), vascular ( n=6), degenerative ( n=5), anomalous ( n=3) and those with an unremarkable MRI ( n=32). There were two independent predictors of abnormal MRI findings: severity of clinical signs and presence of spinal pain. Abnormal MRI findings and speed of onset of disease were significantly associated with survival. For the 32 cats with unremarkable MRI findings, only nine died due to spinal disease and, therefore, the median survival time (MST) was not reached (lower 95% confidence interval (CI)=970 days). For the 60 cats with abnormal MRI findings, 37 died due to their disease and the MST was 138 days (95% CI: 7–807).

The dimensions of the left atrium in cases with mitral regurgitation are an indirect measurement of its severity. The objective of this study was to evaluate the value of a new radiographic measurement, the radiographic left atrial dimension (RLAD), for detecting left atrial enlargement (LAE) in dogs. Thirty one dogs without LAE and 46 dogs with LAE were recruited in a prospective fashion. Reference left atrium dimension was measured by standard left atrium to aorta ratio (LA/Ao) by 2D echocardiography. LAE was considered if LA/Ao > 1.6. Left atrium dimension was then quantified on lateral radiographs by measuring RLAD. Vertebral heart size (VHS) was measured and RLAD was obtained by drawing a line bisecting the 90 degrees angle defined by the long and short cardiac axes lines of the VHS, up to the dorsal edge of the left atrium and comparing its length to T4’s vertebral body length. The correlation of VHS and RLAD methods with LA/Ao was estimated, as well as their sensitivity and specificity for detecting LAE. Receiver Operating Characteristic (ROC) curves were used to estimate the optimal decision criteria for each method. A positive correlation was observed between RLAD and LA/Ao (r = 0.82). RLAD’s sensitivity and specificity for detecting LAE when evaluated at the optimal cut-off value, 1.8 vertebrae, were 93.5 and 96.8% respectively. RLAD showed high reproducibility and repeatability. RLAD appears to be a clinically useful radiographic measurement for evaluating left atrial dimensions. RLAD would provide clinicians with a simple and cost-effective tool for evaluating and monitoring LAE.