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

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 dorso-ventral (DV), ventro-dorsal (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 cardio-thoracic 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.