Parasites of swine / Maurice C. Hall.

  • Maurice Crowther Hall
Date:
[1924]
Catalogue details

Licence: Public Domain Mark

Credit: Parasites of swine / Maurice C. Hall. Source: Wellcome Collection.

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    on casual examination for trichinae or sarcosporidia. So far as -known, they are of no importance from the standpoint of veterinary practice or meat inspection. Treatment.—None known. Prophylaxis.—None known at present owing to our ignorance of the exact identity and life history of the parasite. FASCIOLA HEPATICA Linnaeus, 1758 The common liver fluke Synonym.—Distomum hepaticum (Linnaeus, 1758) Abildgaard. Hosts.—Primary: Swine, sheep, cattle and other hosts (See Para¬ sites of Sheep); secondary: Snails (See Parasites of Sheep). Location.—Biliary canals, bile duct, cystic duct and common duct of primary hosts, and as erratic parasites in the lungs, spleen and heart, also retropleural, retroperitoneal, subcutaneous and elsewhere; in liver of secondary hosts. Morphology.—Flattened, leaf-like parasites (Fig. 2), about an inch long, as a rule. For details of structure see Parasites of Sheep. Fig. 2. Fasciola hepatica. Entire worm. Ventral view. Natural size. From Stiles, 1898. Life history.—Involves intermediate stages in snails. For details see Parasites of Sheep. Distribution.—Widely distributed over the world. Occurs in the United States, especially in the South. Dr. Dalrymple tells me that this fluke is found in perhaps 1 per cent of the swine around Baton Rouge. Pathology.—The clinical features of hepatic distomatosis in swine have been described by Frenkel. He recognizes 2 types of the disease. One type is gall duct distomatosis and the other parenchymatous dis¬ tomatosis. The first is characterized by cholangitis, the flukes being present in the gall ducts and gall bladder. The second is an acute, subacute or chronic parenchymatous hepatitis, which may go on to a chronic interstitial hepatitis, and is associated with immature flukes in the liver parenchyma. In the latter condition the capsule of the liver is frequently roughened and adhesions to the peritoneum may occur. Palpation of the liver surface often reveals small inequalities and the 8
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