01.03.2016 | Case Report | Ausgabe 2/2016
Vacuolar myopathic lesion in a Holstein-Friesian dairy cow affected with bovine dilated cardiomyopathy: a preliminary report
Comparative Clinical Pathology
- S. Ohfuji
Occurrence of vacuolar myopathy caused by factors other than inherited glycogen storage condition is uncommon in domestic animals. This preliminary report describes the detection of a vacuolar myopathic lesion in a 13-year-old Holstein- Friesian dairy cow which showed an 8-day history of cardiac disease. Gross inspection after slaughter revealed edema in a variety of tissues, dilatation and hypertrophy of the cardiac ventricles, and hepatic congestion. Histopathology revealed degenerative myocardial lesions and passive hepatic congestion, which were identical to those previously documented in cases of bovine dilated cardiomyopathy. Skeletal muscles represented a vacuolar myopathic lesion characterized by the presence of distinctive vacuoles in atrophic myofibers, which occurred singly in the central zone of each myofiber on transverse sections and showed an irregularly elongated appearance on longitudinal sections. Such vacuoles frequently contained a small amount of weakly eosinophilic, granular, debris-like, or amorphous substances, displaying a feature of autophagic vacuoles. These vacuolated myofibers were more prominently observed in some muscle fascicles of the longissimus thoracis muscle than other muscles examined. The vacuolar myopathic lesion recognized in this cow was similar to some degree to that of autophagic vacuolar myopathy in man. Further studies are necessary to clarify a causal relationship between this vacuolar myopathic lesion and the disorder of bovine dilated cardiomyopathy.