Insights into the Intestinal Pathogenesis of Peste des Petits Ruminants in Sheep and Goats

Background:

Peste des petits ruminants (PPR) is a highly contagious and economically important viral disease of sheep and goats, posing a major threat to livestock production and food security in developing regions. While pulmonary and systemic manifestations of PPR virus (PPRV) infection are well documented, the intestinal pathology remains poorly described.

Methods:

Twenty-one small ruminants (15 goats and 6 sheep) of varying ages were examined for clinical signs, gross lesions, and intestinal pathology. Intestinal samples were processed for histopathology, histomorphometry, and immunohistochemistry to detect PPRV antigen and inflammatory cytokines (IL-1 and NF-κB). Data were analyzed descriptively and inferentially at α = 0.05.

Results:

Most affected animals (85.7%) were ≤1 year old. Sheep exhibited more severe gastrointestinal signs (89%) than goats (63%), while goats showed greater systemic and respiratory involvement (91%). Intestinal lesions such as button ulcers and zebra stripes were more frequent in sheep (77%) than goats (59%). Histopathology revealed variable villous atrophy, stunting, matting, clubbing, forking, and necrosis, with sloughing of enterocytes and cryptal cell necrosis. Some cases showed cryptal hyperplasia and submucosal lymphocytic infiltration, suggestive of early infection. Notably, mucosal-associated lymphoid tissue hyperplasia and cytokine (IL-1, NF-κB) expression were more pronounced in goats. PPRV antigens were strongly immunolocalized in both enterocytes and cryptal cells, confirming viral replication in intestinal tissues.

Conclusion:

PPRV infection produces significant enteric pathology in small ruminants. Goats exhibit stronger mucosal and cytokine responses than sheep, indicating species-specific differences in intestinal pathogenesis and immune modulation.