During the last three years a new disease has caused heavy losses to the industry farming the hybrid catfish , 'Pla Big Oui', in Thailand. The disease, known as 'catfish jaundice', or 'yellow catfish disease' was first recorded in central Thailand in early 1990. Financial losses due to this disease are heavy because the disease affects large, market sized fish. One of the first signs of the disease is a reduction in appetite. Mortality rates then increase rapidly and clinical signs of jaundice are observed.
Affected fish show yellow pigmentation of the gills and skin.
By the time the yellow coloration develops the fish are usually anorexic and moribund. Mortality rates are usually very high. Diseased fish range in size from 150g to 350g. Eighty per cent of the affected farms use chicken offal from processing plants as the only source of fish feed. A few affected farms use trash fish and pelleted feed combined.