Acute and chronic canine parvovirus myocarditis following intrauterine inoculation

Canine myocarditis virus was inoculated into puppies in utero 8 days before parturition. Puppies were clinically normal at birth. One puppy died 23 days after inoculation and a second puppy was comatose before euthanasia on day 27 post inoculation. Both had acute, non-suppurative myocarditis, and parvovirus was isolated from the heart of each pup. Two other puppies remained clinically normal until euthanasia at 87 and 131 days after inoculation. These latter puppies had extensive, focal fibrosis within the myocardium. Despite weekly monitoring, ECG changes were not recorded. The apparent predilection of canine parvovirus for cardiac myocytes is discussed.