Introduction

The immunohistochemistry (IHQ) is a diagnostic method which utilizes monoclonal antibodies to identify antigens and in the case of canine distemper virus (CDV) are formalin-fixed tissues. For its interpretation and application, it is recommended to pay special attention to variables such as age, stage of infection, the tropism of the virus in different tissues, among others.

Objectives

The aim of the study was to apply the IHQ technique to determine the presence of CDV in formalin-fixed tissues embedded in paraffin. To do this, cases were analyzed by histopathology between 2007 and 2013. Thirty-six cases were taken at three laboratories with clinical and pathological diagnoses of CDV.

Methods

Respiratory system, nervous and lymphoid tissues given the tropism and injuries associated with this virus infection evidenced at necropsy and histopathology were selected.

Results

It was found that the tissues which showed higher immunologic marking were lung and lymph node (5 cases: 20% each), brain (4 cases: 16%), spleen (3 cases: 12%), and, finally, tonsil (2 cases: 8%). Excellent levels of agreement between the results obtained by IHQ and by histopathology in lung (82%) were also found; the level was acceptable in lymphoid tissue (38%) and not very good in brain tissue (28%). In addition, lesions compatible with other viral entities that are mistakenly diagnosed as CDV were found.

Conclusions

Based on the results obtained, it was concluded that an excessive diagnosis of CDV by histopathology necessitated the use of IHQ for case confirmation.