ABSTRACT
In many countries the perception of a high disease prevalence is widely held but the true incidence is not known; respiratory infections represented only 5.6% of sheep submissions to veterinary laboratories in the UK in 2008. The presumptive clinical diagnosis of acute respiratory disease caused by Mannheimia haemolytica and Bibersteinia trehalosi (‘pasteurellosis’) in
growing lambs (Fig. 7.1) and adult sheep (Fig. 7.2) is based upon ndings of sudden severe illness, inappetence, pyrexia, marked toxaemia and tachypnoea consistent with endotoxaemia. However, many other infectious diseases have a similar clinical presentation (Fig. 7.3). Respiratory infections often result from adverse physical and physiological stress (Fig. 7.4) combined with viral and bacterial infections; virus infection alone does not cause acute respiratory disease.
