Bacillary hemoglobinuria in a dairy cow in Goiás State, Central-West Brazil, without demonstrable evidence of active fascioliasis.

In a dairy herd in the state of Goiás, Central-West Brazil, a cow died following an acute illness characterized by jaundice and hemoglobinuria. Necropsy revealed jaundice, dark-red urine and dark-red discoloration of the kidneys, and a diffusely copper-colored liver with two extensive, firm lesions surrounded by hyperemic halos in the right and left lobes. Histopathological analysis showed multifocal coagulative necrosis in the liver, accompanied by abundant intralesional bacillary structures and multifocal thrombosis. Renal lesions included tubular cell degeneration and necrosis, intracellular hyaline droplet accumulation, and occasional proteinaceous casts within the tubular lumen. PCR and sequencing confirmed the presence of Clostridium haemolyticum DNA in the liver lesions. Based on the characteristic clinical presentation and pathological findings, the diagnosis of bacillary hemoglobinuria was established, with further molecular evidence of the clostridial agent. To our knowledge, this is the first reported case of bacillary hemoglobinuria in the Central-West region of Brazil, and an unusual report in the Tropical Zone in the country, especially in dairy cattle.