Leptomeningitis / Ventriculitis / Choroiditis Syndrome (Histophilus somni) in cattle

description of three outbreaks in Eastern Uruguay

Abstract

The aim of this paper is to describe three outbreaks (four cases) Leptomeningitis / Ventriculitis /Choroiditis Syndrome (Histophilus somni) occurred in cattle in the eastern region of Uruguay (2013-2019). All cases occurred in feedlots and cattle farms with intensive o semi-intensive production systems. Animals showed fever, ataxia, opisthotonus, seizures, and finally death. At necropsy the main findings were found in the central nervous system and characterized by fibrino-suppurative leptomeningitis, with ventriculitis and choroiditis. Pericarditis and nephritis- pyelonephritis were also found in some cases.  No pulmonary lesions were found, in the four animals necropsied. The main histological lesions were found in the periventricular region and characterized by vasculitis, thrombosis with Gram-negative bacterial colonies. In two cases, the presence of Histophilus somni in brain and kidney lesions was confirmed by immunohistochemistry. Bovine histophilosis is a disease present in Uruguay and it should be considered in case of mortality of animals with nervous and multisystemic infections.