Introduction
This condition was first identified in broilers in Pakistan in 1987. It spread rapidly in broiler producing areas in that country and the same or a very similar condition has been seen in North and South America. It affects mainly broilers and broiler parents in rear and has also been seen in pigeons. It is a condition caused by an adenovirus, possibly in combination with an RNA virus and immunosuppression caused by Chick Anaemia Virus or Infectious Bursal Disease. The disease is readily reproduced by inoculating birds with a bacteria-free filtrate of a liver extract from an affected bird. Mortality may reach 60% but more typically 10-30%.
Signs
- Sudden increase in mortality.
- Lethargy.
- Huddling with ruffled feathers.
- Yellow mucoid droppings.
Post-mortem lesions
- Excessive straw-coloured fluid distending the pericardium (up to 10 mls).
- Enlarged, pale friable liver and kidney.
- Congestion of the carcase.
- Lungs oedematous.
Diagnosis
Lesions, histopathology, virology.
Treatment
None. Good water sanitation (e.g. treatment of drinking water with 0.1% of a 2.5% iodophor solution) appears to be beneficial.
Prevention
The condition typically occurs in areas of high poultry density where multi-age operation is traditional. Control of predisposing immunosuppressive diseases may help limit losses. Formalin-inactivated oil adjuvant vaccines are reported to be highly effective and are used in areas where the condition is endemic.