Studies on the pathogenesis of heart lesions in dogs infected with pseudorabies virus.

Pseudorabies virus was inoculated by various routes into dogs to determine the relationship of pseudorabies virus to the development of heart lesions. Electrocardiograms and serum samples for lactate dehydrogenase isoenzymes were taken twice daily. Transitory and persistent arrhythmias were a consistent finding. Heart lesions were noted within each of the inoculated groups. These changes varied from severe multifocal areas of hemorrhage and myocardial degeneration to small zones of myolysis. A ganglioneuritis of the stellate ganglia and autonomic ganglia within the heart were also consistent findings. Herpes-like viral particles were found by electron microscopy in various autonomic ganglia and in myocardial endothelial cells. No viral particles were found in myocardial cells. Significant increases in lactate dehydrogenase-1 were noted. It was concluded that fatal arrhythmias resulted from pseudorabies virus infections in the dog after the occurrence of myocardial and ganglionic lesions.