Left ventricular non-compaction cardiomyopathy in eight guinea pigs (Caviaporcellus)

Left ventricular non-compaction cardiomyopathy (LVNC) is a rare form of myocardial disease in humans, and only three animal case reports have been published. We report on LVNC in eight guinea pigs.

Between 2018 and 2023, LVNC was identified in eight hairless Skinny breed guinea pigs (Cavia porcellus) aged 2-4.5 years that were referred for cardiac evaluation. Physical and echocardiographic examinations were performed. Echocardiographic findings were compared to those of a matched case-control group comprising eight apparently healthy guinea pigs. Seven of the eight animals with LVNC had congestive heart failure. Two underwent necropsy with cardiac histopathological examination.

Four animals had a familial relationship within two litters. The other four were not related. Echocardiographic examination in all affected animals identified regions of left ventricular trabecular, spongy, non-compacted endocardium and endomyocardium. Left ventricular enlargement, systolic dysfunction, and enlargement of the left atrium were noted in seven of eight animals; pericardial effusion was present in four guinea pigs. The seven animals with congestive heart failure were treated with furosemide and pimobendan. Median survival time after diagnosis was 127 days (range: 7-270 days). Postmortem examination was conducted in two of these eight animals and presence of LVNC was confirmed.

Only two guinea pigs underwent necropsy, the gold standard in the diagnosis of LVNC. Thoracic radiographs were not taken and electrocardiography was not performed. Treatment choices were based on criteria used in dogs and cats.

Left ventricular non-compaction cardiomyopathy exists in guinea pigs. Familial relationships among affected animals suggest the possibility of a genetic etiology. Echocardiography was suitable to detect endomyocardial changes consistent with LVNC. Postmortem examination confirmed the LVNC diagnosis with additional involvement of the right ventricle in some animals.