Occurrence: Worldwide. Species affected: All, specificity depending on Capillaria species. Less common in chickens. Age affected: All

Causes: Parasitic nematode worms of the genus Capillaria.

Effects: Depending on Capillaria species involved- In heavy infestations, these worms are extremely pathogenic and can result in death. In chickens, they are less pathogenic. Symptoms include malnutrition and emaciation associated with severe anaemia.

Worms of the genus Capillaria are found in the mucosa of the mouth, oesophagus and crop. The body is thread-like, attenuated anteriorly and posteriorly; head with (C. annulata) or without (C. contorta) a cuticular swelling. The male is 8-17 mm long, 60-70 mm wide, has two terminal laterodorsal prominence on tail end a spicule very slender and transparent, about 800 mm long, 120-150 mm wide; the vulva is prominent, circular, and 140-150 mm posterior to beginning of intestine.

The cycle is direct for C. contorta and indirect for C. annulata, which requires the earthworm as an intermediate host. Eggs pass out the rectum and embryonate on the ground or in the earthworm in about 1 month. Embryos or earthworms containing the embryos, are consumed by the bird. Worms mature in the host in about 1 month.

When present in large numbers, these worms are extremely pathogenic and can result in death especially in turkeys, partridges, pheasants, guinea and quail. They are less common and less pathogenic in chickens. Signs are principally malnutrition and emaciation, associated with severe anaemia. Usually there is inflammation (thickening and roughening) on the crop and oesophageal walls.

When present in large numbers, these worms are extremely pathogenic and can result in death especially in turkeys and game birds. They are less common and less pathogenic in chickens. Signs are principally malnutrition and emaciation, associated with severe anaemia. Usually there is inflammation, thickening and roughening on the crop and oesophageal walls.

Coumaphos and Hygromycin B are both approved only for use in chickens. Coumaphos is given to replacement pullets in feed (0.004%) for 10-14 days prior to the onset of egg production. It is given to layers (0.003%) for 14 days as needed, but no sooner than 3 weeks after the end of the preceding treatment. Coumaphos was reported to be effective against A. galli, H. gallinarum, and C. obsignata. In Western Europe, only Flubenol is licensed.

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