Abstract:
Developmental stages of Dictyocaulus filaria (Rudolphi, 1809) were recovered from the right colic
mesenteric lymph nodes of lambs 18 hours after infestation . The majority of the parasites remain in the
lymph nodes until Day 6 and from Day 7 onwards migrate via the thoracic duct to the heart and pulmonary
arteries. From Day 8 to Day 14 parasites occur in considerable numbers in the lung tissue. Although
some worms may be present in the trachea and bronchi on Day 4, they are not present in large numbers
prior to Day 10. From the 12th day the numbers in the lung tissue decrease while those free in the respiratory
passages increase.
