Canine adenovirus (CAV) is the most pathogenic of the mammalian adenovirus species. There are two serotypes. Type I can cause infectious hepatitis in dogs (acute septicemia characterized by necrosis of the hepatic lobular center, inclusion bodies in the hepatic parenchymal cells and cortical nuclei, and prolonged bleeding time). It can also cause fox encephalitis, so it is also called fox encephalitis and infectious liver disease in dogs. Type II can cause infectious laryngotracheitis and enteritis in dogs.