494 Worms in the Tntfstinal Tract. 



Natural infection takes place, according to Marmotel, on 

 wet, marsliY pastures during the months of August and Septem- 

 ber; but it prol^ablv takes place also during sojourn in the barn 

 if the latter offers conditions favorable to the development of 

 embryos from the deposited ova. 



The pathologic significance of the larvaj of Oesophagostomum living in the intes- 

 tinal wall is not solely confined to a detrimental effect upon the function of the intes- 

 tine by numerous worm nodules, but also in the absorption of numerous pathologic 

 bacteria for which these nodules form a portal of entrance; this may become the 

 cause of secondary infection. 



Anatomical Changes. In the small intestine and cecum of 

 cattle, and in the large intestine of other animals, tubercular 

 nodules (roundworm nodules) are found often isolated; fre- 

 quently also in great numbers, in hundreds and thousands. 

 (Drechsler once counted 430; Marotel saw in one case 4,000 in 

 the small intestine and 1,000 in the large intestine.) The nodules 

 vary from the size of a pinhead to that of a pea, and they may 

 occasionally be as large as a hazelnut ; the smallest ones have a 

 blackish color, the medium-sized nodules are blackish to grajdsh- 

 white, the larger ones are always grayish-white. The otherwise 

 unchanged intestinal mucosa shows half-spherical projections; 

 it appears somewhat thinner at this place and in hogs it is also 

 ulcerated. The nodules are mainly composed of a thick con- 

 nective tissue capsule which may contain a small amount of 

 caseous, and in the larger nodules purulent, matter; the latter 

 may have become calcareous. The younger nodules contain 

 larvae of Oesophagostomum measuring 3-4-7 mm. 



Symptoms. xV few nodules are frequently found, in slaugh- 

 ter houses, in the intestines of animals which did not show any 

 symptoms of disease during life. Morbid s^anptoms are only 

 observed in intense invasion and they consist in untractable pro- 

 fuse diarrhea, progressive emaciation, anemia and cachexia. 

 The disease then usually terminates fatally in coma which comes 

 on after two to three months. When the disease appears as an 

 enzootic one-half of affected animals may die. 



Diagnosis. The occurrence of the above mentioned S3^np- 

 toms following sojourn on wet, marshy pastures may suggest 

 oesophagostomiasis nodularis, but a reliable diagnosis can only 

 be made on the basis of some postmortem examinations, since 

 the ova of Oesophagostomum are not yet known ; the differential 

 diagnosis has to consider gastro-intestinal strongylosis (see 

 page 457) and enteritis paratuberculosa (see Vol. I). 



Treatment. This must be confined to a forced nutrition of 

 the patients. Prophylactic measures are those recommended 

 for gastric strongylosis (see page 458). 



Literature. Drechsler, D. Z. f. Tm., 1876, II, 355.— Marotel, Journ. Vet., 



1908, r,22 (Lit.).— V. Ratz, B. t. W., 1891, 223.— Scheber, Fortschr. d. Vet.-Hvg., 

 1905, 97.— Seller, D. t. W., 1902, 345 (Lit.). 



