The clinical and Pathological features of experimental Mannheimia Hemolytica A2 infectionin West African Dwarf Goats.

Abstract

Mannheimiosis due to Mannheimia hemolytica was experimental y induced in 15 six -month-old West african dwarf goats by intratracheal inoculation of 1 x 109 colony-forming units of four hour log-phase Mannheimia hemolytica serotype A:2 with five goats serving as controls. The clinical signs were observed and two goats were euthanized at predetermined intervals for bacteriological and pathological investigations on tissues col ected using standard techniques. The clinical signs in order of manifestation were anorexia, pyrexia, dyspnea, nasal discharge, recumbency and death. The prominent lesions observed at necropsy were pulmonary congestion and edema with consolidation and pleural adhesions of the apical lobes, fibrinous pleurisy as wel as, petechial and ecchymotic hemorrhages of skeletal muscles. The average percentage lung consolidation for the infection was 10.0% with no significant sex variation (P>0.05) and the right lung was more affected (p Keywords: Goat – Pneumonia – Mannheimia hemolytica, Experimental infection – Nigeria. Mannheimiosis causee par Mannheimia hemolytica a ete provoque experimentalement chez 15 chevres naines d’Afrique de l’ouest âgees de six mois par inoculation intra tracheale de 1 x 109 d’unites formant colonies de phase de croissance logarithmique de quatre heures de Mannheimia hemolytica de type serologique A:2 avec cinq chevres servant de temoins. Les signes cliniques ont ete observes et deux chevres ont ete euthanasiees a des interval es predeterminees pour faire des analyses bacteriologiques et pathologiques sur les tissus preleves a l’aide des techniques usuel es. Les signes cliniques par ordre d’apparition etaient l’anorexie, la pyrexie, la dyspnee, l’ecoulement nasal, le decubitus et la mort. Les observations importantes faites a l’autopsie etaient la congestion pulmonaire, un oedeme avec une hepatisation et des adherences pleurales des lobes apicaux, la pleuresie fibrineuse ainsi que des petechies et ecchymoses hemorragiques des muscles squelettiques. Le pourcentage moyen de l’hepatisation des poumons pour l’infection etait de 10,0% sans variations remarquables entre les sexes (P>0,05) et le poumon droit etait le plus touche (p Mots cles: Chevres, pneumonie, Mannheimia hemolytica A2, infection experimentale