M-mode, two-dimensional and Doppler echocardiographic findings in 40 healthy domestic pet rabbits

Abstract Objectives The aim of the study was to report normal two-dimensional, M-mode, and Doppler echocardiographic findings from a large cohort of healthy, manually restrained, adult pet rabbits. Animals and methods Forty healthy pet rabbits [22 Dwarf Lops (DL), 14 French Lops (FL) and 4 Alaskan (AL)] underwent a full physical examination and conscious two-dimensional, M-mode, and Doppler echocardiography. Results The median age of the rabbits was 21.5 months, the median weight was 2.9 kg (DL: 2.4 kg, AL: 4.35 kg, FL: 6.0 kg). Echocardiography with ECG monitoring was feasible in all rabbits. Left atrial and ventricular dimensions were significantly larger in FL as compared to DL; overall, a positive correlation with weight was present. No significant differences between breeds were identified for flow velocities. Trace regurgitation was detected at the aortic valve in 7/40 (17.5%) rabbits, at the tricuspid valve in 5/40 (12.5%) and at the pulmonic valve in 1/40 (2.5%) rabbits. Mitral inflow E and A waves were summated in 60% of cases. Conclusions The results of this study can be used as echocardiographic values in FL and DL for comparison with clinical cases, and may also be applicable for other breeds of similar sizes. Breed specific values should be used when measuring left atrial and ventricular sizes. However, no breed or size differences were found for the rest of the echocardiographic parameters, which may therefore be applicable for the general pet rabbit population.