12th Ljudevit Jurak International Symposium on
Comparative Pathology
June 1-2, 2001

Fabio Del Piero
University of Pennsylvania, School of Veterinary Medicine, Department of Pathobiology and Clinical Studies, New Bolton Center, Kennett Square, USA
Key words: virus, intestine, equine, ruminant, pig, avian, fish, dog, cat, production and companion animals.
 Numerous viruses are able to infect the intestine and cause significant damage. Targeted cells can be almost any of the cells comprising the intestine, but are mainly represented by enterocytes, macrophages and endothelia. Lesions generally include intestinal gland and lymphoid tissue necrosis, vasculitis with thrombosis and, in the case of herpesvirus, adenovirus, morbillivirus and parvovirus infection, presence of inclusion bodies. The following viruses are responsible for intestinal infection: equine herpesvirus 1 and equine arteritis virus in equids; bovine virus diarrhea pestivirus, rinderpest morbillivirus, pest des petite ruminants morbillivirus, bovine herpesvirus 1, bovine adenoviruses, bovine rotavirus, bovine coronavirus, blue tongue orbivirus, foot and mouth disease aphthovirus in cattle, small domestic and wild ruminants, and camelids; porcine reproductive and respiratory syndrome arterivirus, transmissible gastroenteritis coronavirus, porcine epidemic diarrhea coronavirus, hog cholera pestivirus, African swine fever virus, porcine circovirus 2, porcine adenovirus 3, porcine enteroviruses, hemagglutinating encephalomyelitis virus, porcine parvovirus, porcine rotaviruses in swine; avian influenza orthomyxoviruses, Newcastle disease paramyxovirus, hemorrhagic enteritis adenovirus and Marek’s disease herpesvirus in birds; nodavirus, infectious salmon anemia virus and infectious pancreatic necrosis rhabdovirus in fish; canine parvovirus 1 and 2, canine herpesvirus and canine distemper morbillivirus in canids; feline parvovirus, feline infectious peritonitis and enteritis coronaviruses, feline immunodeficency lentivirus, feline leukemia retrovirus; rabbit hemorrhagic disease calicivirus in lagomorpha; viruses affecting several species include influenza orthomyxoviruses, rabies rhabdovirus, Australian bat lyssavirus, porcine herpesvirus (PHV), eastern equine encephalitis alphavirus, West Nile fever flavivirus. The prion agents of transmissible spongiform encephalopathies of ruminants can be detected in M cells and lymphoid intestinal tissue. This review, written for the benefit of pathologists, clinicians, immunologists and virologists, includes a description of numerous viral diseases affecting the intestine of animals. Emphasis is placed on suggestive or pathognomonic lesions, target cells and tissues and cellular localization. The virus localization refers to the virus distribution detected using immunohistochemistry, which allows for a rapid and accurate diagnosis and improves our understanding of the pathogenesis of infectious diseases and is often more sensitive and specific than conventional virus isolation.