Worms

Occurrence: worldwide on birds reared on reused litter. Ascarids, Capillaria, tape worms are helminths or worms and are very common internal parasites.
Species affected: All birds.
Age affected: All. 

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Causes

Ascarida most common of round worms seen in poultry. Ascarida galli is the most common ascarid This worm exists in the lumen of the intestine, occasionally in the esophagus, crop, gizzard, oviduct, and body cavity. It is a white round worm that is 50‑76 mm long and 490‑1.21 mm wide. 

Ascaridia infection causes weight depression in the host, which correlates with increasing worm burden. A. galli has also been shown to contain and transmit viruses, and bacteria. The Capillaria (crop worm) is found in the mucosa of mouth, esophagus and crop. The body is thread‑like, attenuated anteriorly and posteriorly and is 8‑17 mm long, 60‑70 mm wide, has two terminal laterodorsal prominences on tail end, a spicule, very slender and transparent, about 800mm long and a spicule sheath covered with fine hair‑like processing.  Tape worms are white, flat segmented “ribbon shaped”. There are many species of tapeworms.

Mode of transmission

Male and female ascarid adults copulate in the intestine and produce eggs, which pass on the ground and after embryonation are infective to the bird. This life cycle is direct. 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. Flatworm sp. require an invertebrate intermediate host. Flies and their larvae are common carriers of tapeworm eggs.

Clinical signs

Chickens infected with a large number of Ascarids suffer from loss of blood, reduced blood sugar content, increased urates, shrunken thymus glands, retarded growth, and greatly increased mortality. A. galli can transmit viruses, and bacteria. Capillaria present in large numbers are extremely pathogenic and can result in death, especially in turkeys, partridges, pheasants, guinea and quail. They are less common and less pathogenic in broilers, but more so in broiler breeders. Signs are principally malnutrition and emaciation, associated with severe anemia. Usually there is inflammation (thickening and roughening) in the crop and esophageal walls. Flatworms are common in egg layers reared over pits containing built up litter with fly problems.

Postmortem lesions

Worms cause inflammation and enlargement of the intestinal tract. In severe infections, intestinal blockage can occur.

Diagnosis

Presence of adults worms in the intestines.

Treatment & control

Piperazine and levamisole hydrochloride by drinking water for 3 to 4 hours for round worms only. Poultry litter treatment and insecticides for killing intermediate host.