Alterações estruturais e marcação imonohistoquímica do parasitismo no intestino de cães (Canis familiaris) (Linnaeus, 1758) naturalmente infectados por Leishmania (Leishmania) infantum (Nicolle, 1908)

Abstract

Canine visceral leishmaniasis (CVL) is a parasitic disease characterized by a clinical or asymptomatic disease. Although few studies of parasitism of Leishmania sp in intestinal tract in dogs have been undertaken. The goal of this research was to evaluate the structural changes and the Immunohistochemical detection of Leishmania (Leishmania) infantum in formalin-fixed, paraffin-embedded sections of canine intestines. Fragments of intestines from 36 dogs with a positive parasitological and serological exams for L. (L.) infantum were obtained and analyzed by histopathology (Hematoxilin and Eosin stain -HE) and immunohistochemistry assays (strepto-avidin -peroxidase). No macroscopic changes were found. Histopathological evaluation showed lymphohistiocytic- plasmocytes infiltrates in 88.88% (32/36) of duodenum, 86.11% (31/36) of jejunum, 97.22% (35/36) of ileum, 91.66% (33/36) of cecum, 86.11% (31/36) of colon and 72.22% (26/36) of rectum section, particularly in the mucous membrane, submucosa and muscularis mucosae. The circulatory changes as hyperemia, hemorrhages and congestion were found in 66.66% (24/36) of duodenum, 69.44% (25/36) of jejunum, 69.44% (25/36) of ileum, 77.77% (28/36) of cecum, 80.55% (29/36) of colon and 77.77% (28/36) of rectum fragments. Amastigotes forms of L. (L.) infantum were detected by strepto-avidin-peroxidase in from both small and large intestine fragments (22.22%).