Abstract

Evaluation of the heart in terms of its silhouette size and shape and the morphometry of other thoracic organs cannot be ignored diagnostically in small animal practice when history and or results of general examination of a patient reveal clinical signs of cardiothoracic diseases. However, there is a paucity of published work on the radiologic appraisal of cardiac and thoracic dimensions in the Nigerian indigenous dog. The research aimed to establish new reference indices for improved diagnosis of cardiothoracic pathologies in the Nigerian indigenous dog. A total of 120 thoracic radiographs of thirty healthy Nigerian indigenous dogs, comprising right lateral, left lateral, dorsoventral and ventrodorsal projections, were obtained and evaluated. Biometric parameters were taken of each research radiographs, recorded, and used to generate cardiothoracic measurement indices for the Nigerian indigenous dog. In the dorsoventral versus ventrodorsal projections, ratios established and described as means plus or minus standard errors of means were as follows: cardiac width/cardiac length ratio 0.75±0.01/0.73±0.01; cardiac length/thoracic diameter 0.64±0.01/0.70±0.01; and heart width/costocostal distance ratio 0.58±0.01/0.60±0.01, respectively. The mean results obtained in the right lateral versus left lateral radiographs were: postcava-to-long axis ratio 0.14±0.00/0.15±0.00; cardiac axes ratio 0.75±0.01/0.81±0.01; cavocardiac ratio 0.19±0.01/0.19±0.01; aorticocardiac ratio 0.22±0.0/0.21±0.00; short axis/sternovertebral distance 0.63±0.01/0.63±0.01; and aortic diameter/long axis ratio 0.17±0.00/0.17±0.00, respectively. The cardiac axes ratio and aorticocardiac ratio showed a positive and significant (p≤0.05) relationship with the cardiac short axis in the lateral projections. The indices established in this study are reproducible and easy to use, allowing objective thoracic assessment. All the results are efficient and generated in the present investigation, probably, for the first time in veterinary radiology. The clinical relevance of this research is related to the management of cardiothoracic anomalies.

Key words: Dogs, Measurements, projections, Radiology, Thoracic organs