STRONGYLIN^ 285 



worms may infect the blood and lymph with organisms which cause 

 other diseases through acting as direct carriers in penetrating the in- 

 testinal wall, or by the wounds which they create affording portals of 

 entrance. In such cases a comparatively slight infestation with CEsopha- 

 gostomum would be sufficient for what might prove a fatal secondary 

 effect. 



Treatment. — No effective curative treatment is known. Preventive 

 measures consist in keeping the sheep from low wet areas. Where the 

 disease is prevalent, lambs may be protected from serious infestation 

 by placing them in a dry uncontaminated lot and feeding and watering 

 them from racks and troughs sufficiently elevated that the contents 

 cannot be soiled by droppings from the nursing ewes. 



NoDTJLAR Strongylosis of Cattle. QiIsophaggstomiasis 



(Esophagostomum radiatum (CE. inflatum). Fig. 151. Stron- 

 gylinse (p. 280). — The thickness of the body is nearly uniform over its 

 greater portion; attenuated toward ends. The anterior portion is 

 usually curved in the form of a hook. The cuticular inflation about the 

 mouth (mouth collar) is disk-like, its height a little more than one- 

 fourth of its diameter. The mouth capsule is bordered by a circle of 

 numerous small triangular denticles. The cervical groove and fold are 

 well developed and the cuticle between it and the mouth collar is in- 

 flated. This inflation has a slight constriction at about one-third of the 

 distance from the cervical groove to the mouth collar. The^ lateral 

 membranes begin at the cervical groove and extend well back along the 

 body; near their beginning are two cervical papillae. The bursa of the 

 male has two lateral lobes united by a small median lobe; spicules 700- 

 800 microns in length. The vulva of the female is transversely elongated 

 upon an eminence located just in front of the anus. From the vulva the 

 body rapidly tapers, terminating in a tip which is usually somewhat 

 bent in a ventral direction. 



The female is 16-20 mm. (5/8-3/4 of an inch) in length; male, 14-16 

 mm. (9/16-5/8 of an inch). 



The eggs are oval, 75-80' microns in length by 38-43 microns in 

 breadth. Their segmentation occurs within the body of the female. 



Parasitic in the small and large intestines of cattle. 



While the nodular larval stage of (Esophagostomum columbianum of 

 sheep is usually found in the large intestine, that of (Esophagostomum 

 radiatum of cattle is often found in the small intestine, the nodules 

 usually occurring in the terminal portion with involvement of the region 

 of the ileo-cecal valve and the cecum. 



In other respects what has been said as to nodular disease of sheep 

 will, in its essentials, applj"" to that of cattle. 



