Spontaneous Dilated Cardiomyopathy and Right-Sided Heart Failure as a Differential Diagnosis for Hepatosis Dietetica in a Production Pig.

An experimentally naïve 37.7-kg Yorkshire-crossbred gilt died unexpectedly 2 d after arrival. Necropsy revealed severe dilated cardiomyopathy characterized grossly by markedly dilated ventricles and thinned ventricular walls and interventricular septum. Histologically there was multifocal myofiber attenuation and patchy loss of myofiber cross striations. The liver contained submassive to massive, diffuse hepatic centrilobular hemorrhage and degeneration. These lesions supported a diagnosis of dilated cardiomyopathy with right heart failure and secondary hepatic degeneration due to marked acute passive congestion. To our knowledge, this case is the first report of spontaneous dilated cardiomyopathy in swine and represents a potential diagnostic challenge regarding the differentiation of the cardiac-associated liver lesion from hepatosis dietetica. The diagnosis of dilated cardiomyopathy and right-sided heart failure was supported by the character of the hepatic lesion, absence of typical gross or histologic lesions of mulberry heart disease, and normal selenium levels.