Hydrallantois in cows naturally poisoned by Sida carpinifolia in Brazil

Abstract

Sida carpinifolia is a small subshrub that is distributed throughout Brazil and is responsible for lysosomal storage disease and occasional reproductive problems in cattle, goats, equids, sheep, and deer. We describe herein the clinical, epidemiologic, and pathologic features of hydrallantois in 3 cows naturally poisoned by S. carpinifolia in Rio Grande do Sul State, Brazil. Clinically, all cows had marked abdominal distension and mild ataxia. After natural death or euthanasia, autopsies revealed that the abdominal distension in all 3 cases was caused by severe enlargement of the uterus, which contained 100-120 L of translucent fluid within the allantois, in addition to adventitial placentation. Microscopic evaluation of the placenta revealed marked diffuse edema, sometimes with a myxomatous appearance. Neurons in the cerebellum and obex were swollen, with mild-to-moderate cytoplasmic granular vacuolation. Histochemical examination with lectins ConA, WGA, and sWGA revealed mild-to-marked staining in the cytoplasm of neurons of the cerebellum and medulla at the level of the obex, indicating the occurrence of α-mannosidosis.

Keywords: cattle; hydramnios; lectin; lysosomal storage disease; swainsonine; α-mannosidosis.

Figures 1–6.

Hydrallantois in cows naturally poisoned by Sida carpinifolia (Malvaceae). Figure 1. Eucalyptus spp. culture areas invaded by large numbers of S. carpinifolia. Figure 2. Marked abdominal distension in cow 3 (photographed 3 h after death). Figure 3. Enlarged uterus in cow 2, occupying almost the entire abdominal cavity. Figure 4. Large amount of yellow, clear fluid within the allantois of cow 2. Figure 5. Adventitial placentation in cow 2. Figure 6. Swollen neurons with moderate cytoplasmic vacuolation observed in the medulla of cow 1. H&E. Bar = 150 µm.