Radiographic cardiac indices for healthy New Zealand white rabbits: A reference interval study based on echocardiography

Abstract

This research was intended to identify reference intervals for the radiographic cardiac indices [vertebral heart scale (VHS), radiographic left atrial dimension (RLAD), and vertebral left atrial size (VLAS) of 58 healthy, adult New Zealand white rabbits based on echocardiography. The VHS, VLAS, and RLAD measurements were taken from contrast right lateral (R) and ventrodorsal (VD) thoracic radiographs. The correlations between these radiographic cardiac indices and echocardiographic parameters were then evaluated. The mean values with a reference interval were 7.94±0.31 vertebrae (v) (7.2-8.6 v) for R-VHS and 8.67±0.33 v (7.8-9.2 v) for VD-VHS. The median values with a reference interval were 1.5 v (1-2 v) for VLAS and 1 v (0.7-1.4 v) for RLAD. Body weight and gender had no effect on radiographic cardiac indices. There were positive correlations between all radiographic indices obtained from the R contrast radiographs and the echocardiographic parameters (rs≥0.421, P<0.0001). Excellent intraobserver agreement was determined for the radiographic measurement methods (intraclass correlation coefficients ≥0.818). The contrast thoracic radiography appears to represent a useful technique for the accurate determination of radiographic cardiac indices. The findings can be used as reference values for radiographic cardiac evaluation in both pet and laboratory rabbits.

Keywords

• Rabbit
• radiographic left atrial dimension
• reference range
• vertebral heart scale
• vertebral left atrial size

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