Filicollis Anatis Infection

a helminthiasis of ducks caused by the acanthocephalan Filicollis anatis, which parasitizes the intestinal tract. The parasite is 6–25 mm long and its development involves an intermediate host, the crustacean Asellus aquations. The parasites perforate the wall of the intestine, which develops inflammatory sites and hemorrhages. Cases of severe infection are fatal to ducklings. Treatment involves destroying the parasites with a solution of carbon tetrachloride. The disease is prevented by keeping ducks on dry land or in running water. Water from reservoirs that have been contaminated with Filicollis anatis should not be used for 1½ to two years.