Laboratory 2
THE STRONGYLES
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| Haemonchus sp. This nematode is common in the abomasum of sheep, goat, cattle, and other ruminants. Note the spirally wound ovaries in the female worms which gives them their common name the "Barber pole worm". Size 20 to 30 mm (this is the largest of the abomasal trichostrongyles) |
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| Haemonchus contortus This is the common "barber pole" worm of the abomasum of sheep. This slide shows the bursa of a male worm. Note the asymmetrical dorsal ray which is characteristic of this genus. |
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| Haemonchus contortus This slide shows the vulva flap of a female worm. |
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| The FAMACHA Chart is used to determine the
level of anemia in sheep and goats. In areas where Haemonchus is a
problem in these animals, anemia is mainly due to the level of infection
with this worm. By using this chart, the herder can determine which
animals need treatment and thus treat only those animals that require it.
This may slow the development of drug resistance in the flock and will save
money on drug treatment. The original chart is in color and the color of the mucus membranes is compared to the colors on the chart to determine the relative level of anemia (which is directly related to the level of the Haemonchus infection). |
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| Ostertagia sp. This trichostrongyle of the abomasum is intermediate in size (smaller than Haemonchus and larger than Trichostrongylus). Male 7.5 to 8.5 mm Female 10 to 12 mm |
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| Trichostrongylus sp. One of the many species of Trichostrongylus found in horses and ruminants. Note the very small size of the worm. Male 4 to 5 mm Female 5 to 7 mm |
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| Cooperia curticei Male and Female worms. This worm is commonly found in the small intestine of sheep. Note the small size of these nematodes and their coiled ("watch spring") appearance. Male 4.5 to 5.5 mm Female 5.8 to 7.2 mm |
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| Cooperia curticei This female specimen demonstrates the characteristic "watch spring" appearance of the parasite. The anterior end shows the cervical inflation which is finely striated. |
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| Chabertia ovina NO LONGER TAUGHT, YOU ARE NOT RESPONSIBLE FOR THIS WORM This parasite is commonly found in the large intestine of sheep and cattle. Note the buccal capsule can be seen with the naked eye Male 13 mm Female 18 mm |
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| Chabertia ovina NO LONGER TAUGHT, YOU ARE NOT RESPONSIBLE FOR THIS WORM Mounted specimen to show the large buccal capsule which is directed ventrally. Note the leaf crowns. |
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| Nematodirus sp. This is a relatively long trichostrongyle found in the intestine of ruminants. Note that the anterior end of this worm is thinner than the posterior. Also note the size: Male 10 to 15 mm Female 15 to 23 mm |
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| Nematodirus sp. This slide shows the bursa of the male worm. Note the long spicules which are joined together at the tip by a narrow membrane. These characteristic spicules can be used to identify this nematode as Nematodirus sp. Male 7.5 to 8.5 mm Female 10 to 12 mm |
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| Nematodirus sp. Egg Because of its size (200 X 90 um; about twice as large as other strongyle-type eggs) and shape, this egg is easily identifiable to genus.
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| Oesophagostomum dentatum One of the species of nodular worms of pigs. Note the size: Male 7.5 to 8.5 mm Female 10 to 12 mm |
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| Oesophagostomum dentatum Note the small buccal capsule (A), leaf crowns (B) and a definite cephalic vesicle (C), which is terminated by a ventral groove. |
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| Oesophagostomum dentatum This is a section through a nodule produced in the intestine of a pig by O. dentatum. |
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| Sheep colon infected with Oesophagostomum sp. Note the thickened intestinal wall and the many nodules. |  |
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| Stephanurus dentatus This is the kidney worm of swine and is found in cysts which open to the hilus of the kidney and the ureters. Note the thin cuticle and visible internal organs. Male 25 mm Female 35 mm |
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| Strongylus vulgaris Whole worms. The females have pointed tails while the males have a bursa at the caudal end. Note the robust nature of these nematodes and their size (smaller than the other species of Strongylus). |
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| Strongylus vulgaris A common nematode of the large intestine of horses. Note the large buccal capsule (A) and the leaf crowns at the anterior end. Two ear shaped teeth (B) are in the buccal capsule and a dorsal "gutter" (C) runs down the dorsal side of the buccal capsule. |
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| Parasitic thrombi of the arteries of a horse due to the larval stages of Strongylus vulgaris. Note the marked thickening of the arterial wall and the thrombus formation. |  |
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| Strongylus equinus Whole worms. Note the size and the robust nature of these nematodes. |
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| Strongylus equinus Note the large buccal capsule and the leaf crowns (C) at the anterior end. There is a dorsal "gutter" (D) with a bifid dorsal tooth (B) at its base and two smaller ventral teeth (A) at the base of the buccal capsule. (You will have to focus up and down to see both ventral teeth.) |
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| Strongylus edentatus Whole worms. Note the size and the robust nature of these nematodes. |
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| Strongylus edentatus One of the largest of the nematodes of the large intestine of the horse. Note the leaf crowns (A) surrounding the mouth, which opens into a large buccal capsule (B). There are no teeth in the buccal capsule of this species, however a dorsal "gutter" (C) is present. The purpose of this gutter is to allow enzymes secreted by glands in the esophagus to make their way into the buccal capsule which would be filled with host tissue while the worm is feeding. |
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| Small strongyles (Cyathostomum spp. Trichonema spp.,
etc.) Whole worms. Note the size (much smaller than Strongylus spp.) A large number of genera and species exist and they vary in size from 5 mm to 15 mm. The males may have large bursa. |
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| Syngamus trachea Occurs in the trachea of turkey, goose, fowl and various wild birds. The sexes are found in permanent copulation, hence the "Y"-shaped appearance of the worm pair. Male 2 to 6 mm Female 5 to 20 mm |
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| Review Question A. The worms in the dish were removed from the colon of a horse which died with severe colic. Give the genus and, if possible, the species of each. B. Indicate which is the more important pathogen. |
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