Histopathological and immunohistological findings in canine parvoviral infection: diagnosis application

In this study, 10 dog puppies, 2 - 12 months old, from different breeds, were used for the comparative evaluation of histopathological findings observed in canine parvoviral infection with immunohistological detection of parvovirus antigens. Dogs exhibited diarrhoea, vomiting and cachexia and after necropsy and histopathological examination, severe enteritis (catarrhal enteritis in 8 cases, haemorrhagic and fibrinous enteritis in 2 cases) was evidenced. Although the intra-nuclear inclusion bodies, pathognomonic of the parvoviral infection, were not observed, some other characteristic signs such as villus atrophy and/or necrosis of the Payer's patches or fibrinous / haemorrhagic enteritis at a lesser extend, were found in 6 cases. The immunohistological detection of viral antigens was also positive for a total of 6 puppies in jejunum / ileum / mesenteric lymph nodes (6 cases), in adrenal glands (3 cases) and also in lungs (1 case). Nevertheless., animals (n = 2) with haemorrhagic and fibrinous enteritis were found negative whereas 2 dogs displaying none of the above histopathological mentioned signs were found positive. These results indicate that in the absence of the pathognomonic sign of the disease, characteristic histopathological signs may not always allow diagnosis and that immunohistochemistry may enhance the diagnosis value.