Encyclopedia of Parasitology

2016 Edition
| Editors: Heinz Mehlhorn

Oesophagostomosis

Reference work entry
DOI: https://doi.org/10.1007/978-3-662-43978-4_2190

Ruminants

Members of the genus Oesophagostomum infect cattle, sheep, and goats. In sheep and goats two species are present: O. columbianum and O. venulosum, the former being considerably more pathogenic. Only one species occurs in cattle: O. radiatum. The life cycle involves a sojourn in the mucosa of the intestine and it is during this larval histotropic phase that the genus has its most pathogenic effects. O. columbianum and O. radiatum infections produce lesions principally in the small intestine, while the other species mainly affect the large intestine (cecum, colon). Third-stage larvae penetrate deep into the mucosa and are enclosed into small  nodules (1–2 mm) by a fibroblastic reaction (Fig. 1). The fourth molt occurs in these nodules. A strong reaction follows  superinfection, and larger nodules are produced (1–2 cm) with retention of L4 in the nodules for long periods.
Oesophagostomosis, Fig. 1

Nodules (arrows) in the rennet bag of cattle

The signs of esophagostomosis are  anorexia, loss of body weight,  diarrhea, and sometimes  edema. A moderately severe normocytic, normochromic  anemia appears, together with a decrease in plasma protein, mainly albumin. Considerable exudation of tissue fluids and plasma proteins from the intestinal lesions and hemorrhages caused by larval emergence contributes to the hypoproteinemia and anemia. This is exacerbated by impaired coagulation. Reduced growth or loss in condition is mainly the result of the interaction between protein effusion into the gut and loss of appetite. Diarrhea presumably results from the loss of absorption capacity of the colon. It would appear that secondary complications and bacterial migration play important parts in the disease.

Swine

The two common species found in pigs are O. quadrispinulatum and O. dentatum. Though the parasites themselves are generally highly prevalent, clinical esophagostomosis is not common in pigs.

Therapy

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Institut für Zoomorphologie, Zellbiologie und ParasitologieHeinrich-Heine-UniversitätDüsseldorfGermany