Clinical‑pathological findings induced by Histophilus somni isolated in subacute cardiac death in feedlot cattle

DE YANIZ, G.; FIORENTINO, A; GARCÍA, J; VIVIANI; SCHOFS, LAUREANO; BENCE, A.; PAOLICCHI, F. ; SANCHEZ BRUNI, SERGIO FABIAN

VETERINARY RESEARCH COMMUNICATIONS

SPRINGER

Lugar: Berlin; Año: 2022

0165-7380

AbstractThe purpose of this report is to provide information about the different presentations of cardiac and extra-cardiac histophilosis and, to assess the antimicrobial (ATM) susceptibility of Histophilus somni isolated from these cardiac lesions todifferent ATM agents commonly used for treating bovine bacterial respiratory pathogens. Eight feedlot calves, which diedafter suffering from food rejection, apathy, hyperthermia, cough and nasal mucous discharge, and lack of response to ATMtherapy, were studied. Cardiac lesions observed at necropsy included valvular/mural endocarditis, myocardial infarction,and necrotizing myocarditis, miliar non-suppurative myocarditis, myocardic necrotic sequestrum, and/or pericarditis. Histopathological, bacteriological and molecular studies confirmed the presence of a fastidious microorganism in the affectedorgans. H. somni showed no resistance to most ATM tested (ceftiofur, gamithromycin, enrofloxacin, florfenicol, tilmicosin).The results obtained in this study confirmed that H. somni was the main cause of the subacute cardiac lesions associatedwith hyperthermia, apathy and respiratory signs observed in cattle examined in this research. These presentations must beconsidered by veterinary practitioners in order to establish a rational therapeutic.