Broiler ascites, first seen in the form of a high altitude disease, has increased in
importance world-wide in direct proportion to the improvement in growth
performance of modern broilers. At the same time, the incidence has spread
gradually from high altitude (above 2000 m) down to sea level, which gave rise
to proposals of alternative causes including infections, toxins and metabolic
disorders. Our work centred on anatomical and physiological aspects and
included hypoxia models, chemotherapy and selection for genetic resistance. The
latter led to the development of ascites-resistant lines, which allowed resistant stock
to become commercially available in South Africa.
The closure of the Poultry Section of the Onderstepoort Veterinary Institute
brought ongoing ascites research to an abrupt end and some of the completed
work was never published. This review of completed, ongoing and planned
ascites work was at the time compiled as final report to the Director of the
Institute in 1990. It came to light again recently and has been edited for
publication. It also includes a new hypothesis on the reasons for the susceptibility
of the domestic fowl and particularly broilers to hypoxic ascites.