An Outbreak of Concurrent Histomonas meleagridis and Enteroccocus fecalis Infection in Ducks

摘要

Seventy four young ducks in a flock of about 300 birds, died of acute hemorrhagic enteritis within 15 days of appearance of the disease. Clinical signs were severe bloody diarrhea, weakness and dehydration. Fecal smears stained with Giemsa's stain showed presence Enteroccocus spp. and red blood cells. Gram stain showed the Enteroccocus spp. occurred singly, in pairs and in short chains and were Gram positive. Postmortem examination showed patchy hemorrhages and ulceration in the small and large intestines as well as the caeca. No worms were seen in the caeca. The liver was enlarged and dark in colour. Histopathological examination showed haemorrhages and mucosal erosion and ulceration in the small and large intestines as well as liver cell necrosis.The intestine mucosa and submucosa contained Histomonas meleagridis. The liver also contained Histomonas meleagridis, occurring singly or in clusters, with its characteristic (double-eyed) structure. It was concluded that the severity of infection of this outbreak was attributed to the concurrent effect of both Enteroccocus and Histomonas infections.