In human pathology the adequate system used to analyze and interprete reactive lymphadenopathies is based on the morphological characterization of the various areas within the lymphoid node. In veterinary pathology there is no standardization of histopathological evaluation of lymph nodes. Therefore, in this study, we applied the Dorfman-Warnke (modified by Burke) human classification of reactive lymphadenopathies to evaluate virus-induced lymphadenitis in guinea-pigs. Canine parvovirus was inoculated into the footpads of guinea-pigs and the response of popliteal lymph nodes was histologically studied. The footpads were excised after different periods of time, processed, and stained with HE, Mallory, Gordon & Sweets, Giemsa and by immunohistochemical methods. A significant increase in the weight of ipsilateral lymph nodes to the inoculation site (p<0.05) was observed. The follicular response in the lymph nodes was characterized by the reaction of the germinative center, which showed partial loss of delimitation in the mantle zone. Increased numbers of blast cells and hypertrophy of post-capillary venules were evidenced in the paracortical area of the lymph nodes. There was a discrete hyperplasia of the medullary cords and a general enlargement of the reticular net associated with those alterations. The reactional response observed was similar to viral lymphadenitis identified in humans, justifying the attempts to systematize this classification for veterinary use just like it is currently done in human medicine.
Canine parvovirus; Lymphadenitis; Animal pathology
