A review on pneumonic pasteurellosis in small ruminants
Dessie Abera, Tesfa Mossie
Abstract
Small ruminant production plays a great role in the livelihood of smallholder farmers. But their production is constrained by pneumonic pasteurellosis. It is a high-priority issue at the national level. So, in this paper, relevant aspects of pneumonic pasteurellosis in small ruminants are reviewed. The disease is most frequent as air is the main route of transmission. They are characterized by high fever, coughing, dyspnoea and muco-purulent nasal discharge that commonly develops in immunocompromized hosts. Stressors being psychological and/or physical are associated with poor management practices. It is a multifactorial disease. But clinical infections are mainly caused by Mannheimia haemolytica, Bibersteinia trehalosi and Pasteurella multocida. Eleven of the known 17 serotypes of M. haemolytica and B. trehalosi have so far been identified in Ethiopia. Virulence factors like cell capsules, fimbriae and endotoxin play a great role in disease development. The disease causes heavy losses that deserve control. However, the presence of multiple serotypes without cross-protection and the development of drug resistance complicated its control. Moreover, the causative agents are normal commensal of the upper respiratory tract which may cause infection in immunocompromized conditions. Therefore, proper management, sound diagnostic methods and the available serotypes should be considered in vaccine preparation.