haemonchus contortus
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Oleh :Yulinar rizky karaman
Adib musta’in Ari purnamasari
Deshinta rizky pramuditha Fanny rufaida Dyah agustini
Haemonchus contortus A species of blood-sucking nematodes
of the genus Haemonchus which may be found in the abomasum of most ruminants and which is the cause of serious losses in sheep from haemonchosis. There have been attempts to subdivide the species, e.g. Haemonchus contortus cayugensis, but the differences between the subspecies have not been substantiated.
PARASITE: Haemonchus contortus, H. placei (stomach worm, twisted wireworm, barber-pole worm)
Host & Habitat : H. contortus is found primarily in abomasum of sheep cattle and goats, occasionally in other ruminant.
May be 30 mm. long. The male is evenly reddish. The spiral
winding of white ovaries around the red intestine creates a barber-pole effect
in the female. The buccal cavity contains a small dorsal lancet. The
male bursa has a characteristic asymmetric dorsal ray. Eggs are 65-80 x
40-45 ju.
Prevalent throughout North America, especially
in the wetter, warmer regions of the continent. Haemonchus is an
important parasite of sheep and domestic ruminants in temperate regions.
Eggs hatch on the ground, and larvae become infective in 4-6 days.
Infective larvae are not very resistant to extremes in temperature or to
desiccation. It is unlikely that larvae overwinter on pasture. The prepatent
period is about 15 days for H. contortus and 28 days for H. placei.
Transmission: Ingestion of infective larvae with food or water.
Major clinical sign is anemia. In severe infections in lambs anemia develops rapidly, and animals die showing
few signs other than anemia or hydremia. In chronic cases the anemia is
accompanied by edema under the jaw and along the ventral aspect of the
abdomen. The skin is pale, the wool may fall out in patches, diarrhea may
alternate with constipation, and appetite is variable. Shortly before death,
animals may become weak and prostrate. At necropsy, pale mucosae,
watery blood, ascites, hydrothorax, and cachexia are the classical gross
signs. Minute petechiae on the abomasal mucosa result from the "bite"
marks of the adult worms.
A dead or dying lamb is usually available for necropsy. Adult
worms may be identified on gross examination.
Best accomplished by providing good nutrition and adequate mineral
supply. Overstocking and wet pastures should be avoided. Use of hay
racks, raised troughs, and pasture rotation will help reduce infection.
Regular treatment is necessary to control this pathogen. Copper sulfate,
phenothiazine, thiabendazole, haloxon, and tetramisole are efficacious.
Bremmer, K. C. 1956. The parasitic life cycle of Haemonchus placei. Aust. J. Zoo/.
4:146-51. Herlich, H., D. A. Porter, and R. A. Knight.
1958. A study of Haemonchus in cattle and sheep. Am. J. Vet. Res. 19:866-72. Roberts, F. H. S., H. N. Turner, and M.
McKevett. 1954. On the specific distinctness
of the ovine and bovine "strains" of H. contortus. Aust. J. Zool. 2:275-95.