SUMMARYTwo types of trichomoniasis, respiratory and intestinal, were found in two duck farms. Based on the morphological features, the organism was identified as Tetratrichomonas anatis.In the first outbreak, main clinical signs were bilateral swelling of infraorbital sinuses, sneezing and profuse diarrhoea with high fatality (300/400) in young ducks. Histological lesions were confined to the upper respiratory tract and lower small intestine and consisted of mucofibrino-purulent sinusitis and catarrhal rhinitis, tracheitis and enteritis. The protozoa appeared frequently in the infraorbital sinuses, the respiratory region of the nose, and the lower small intestine, but rarely in the trachea. In the second outbreak, the lesions were limited to the lower small intestine with catarrhal enteritis in adult ducks clinically showing profuse diarrhoea and low mortality.

Cause and effect diagram, Specification limit, Matrix analysis,