Enzootic Pneumonia - Lambs

• Caused by Pasteurella (Manheimia) haemolytica, possibly together with Mycoplasma ovipneumoniae
• Mainly in late spring/early summer after environmental stress i.e. handling or moving
• May be acute with producing a fibrinonecrotic bronchopneumonia and associated pleuritis
• Or tending towards chronicity with abscessation and fibrous pleural adhesions
• A septicaemic form (mortality 5%) is reported to follow the stress of movement to new pasture in the autumn in weaned lambs.
• Foci of necrosis containing many bacteria are seen at the site of initial invasion in the pharynx and in the liver
• Meningitis in young lambs and mastitis in ewes are other expressions