TREATMENT AND CONTROL BY VACCINATION OF ERYSIPELAS IN FARMED EMUS (DROMAIUS-NOVO-HOLLANDIAE)

Objective To study erysipelas in farmed emus and the treatment and con trol of the disease by vaccination. Design A retrospective study of fi eld outbreaks in emus and challenge experiments in mice using firld an d vacine strains of the organism. Procedure Outbreaks of the disease w ere described. Field strains of the organism were identified and teste d by challenge experiments in mice against commercial vaccine strains. Results Erysipelas was characterised by sudden death in yearling emus . Deaths mainly occurred during the cold wet months. Mortalities of 6 to 10% were seen within the first 7 to 10 days of an outbreak. Clinica l signs were uncommon but some birds exhibited lethargy and greenish d iarrhoea. Necropsy findings included marked petechial haemorrhages on the serosal surface of the large intestine in particular, pericardial effusion and congestion and mottling of the liver. Treatment consisted of individual or mass medication with procaine penicillin, reduction of stress factors such as overcrowding, and spelling and rotation of p addocks. Isolates from two field outbreaks were identified as strain 2 1. Complete protection was provided by a commercial strain 2b vaccine against challenge by strain 21 field isolates in mice. Annual vaccinat ion of birds at 4 weeks and again at 8 weeks of age appeared to contro l further outbreaks on farms where the disease had previously occurred and vaccination appeared to protect for at least 12 months. Conclusio n Treatment of birds with antibiotics may be feasible in the face of a n outbreak. However, annual vaccination of birds with an appropriate v accine is recommended.