Radiologic indices of cardiac mensuration in the African grasscutter (Thryonomys swinderianus)

Abstract

This research aimed to establish reference radiographic indices for future cardio-thoracic appraisals in the African grasscutter. Twenty healthy animals consisting of equal number of juveniles and adults were used. Forty thoracic projections consisting of dorsoventral (DV), ventrodorsal (VD), right lateral (RtL) and left lateral (LeL) views were acquired. The evaluated parameters included thoracic and cardiac diameters on the DV/VD radiographs, and cardiac long and short axes on the RtL/LeL radiographs. Cardiac indices generated were cardiothoracic ratio (CTR), vertebral heart score (VHS) and cardiac axis ratio (CAR). The reference values of CTR on VD and DV were 0.52 ± 0.02 and 0.50 ± 0.02, respectively. The difference was not significant (P > 0.05). The mean radiographic values of CTR for juvenile and adults on DV were 0.48 ± 0.04 and 0.52 ±.0.01, respectively. The reference values of VHS on RtL and LeL were 8.70 ± 0.23 and 8.60 ± 0.21, respectively. The difference was not significant (P > 0.05). The mean values of VHS for juveniles and adults on RtL were 8.20 ± 0.30 and 9.20 ± 0.12, respectively. The difference was not significant (P > 0.05). These indices are relevant in future diagnosis of cardiac diseases in the African grasscutter.