ANIMAL PARASITES 257 



stunted, aiijrmic condition. Stiles reported extreme annnnia, 

 nntliriftiness and many deaths amono; cattle in a certain section 

 of Texas, dne to extensive infection with the Uncinarin radiatus. 



The treatment is largely preventive. Oalves and yearlings 

 should be provided with plenty of feed at all seasons of the year. 

 Good care and careful feeding will keep them in a thrifty, 

 healthy condition and enable them to throw off invasions of 

 intestinal worms. Turpentine is the vermifuge usually admin- 

 istered to calves. The dose is from two to four drams given in a 

 milk or raw linseed oil emulsion. 



Stomach Worm of Sheep. — The twisted stomach worm, 

 Hcemonchus contort us, is the most injurious internal parasite 

 of sheep. It is a very small, hair-like worm from 0.4 to 1 inch 

 (9 to 25 mm.) in length. In the adult form it attaches itself 

 to the mucous membrane of the fourth stomach or abomasum, 

 and lives by sucking blood. The blood present in the digestive 

 tract of the worm gives it a brown color, and the white oviducts 

 which are wound around the digestive canal cause the body to 

 appear twisted. When the twisted stomach wonn is present in 

 large numbers, the worms become mixed with the contents of the 

 stomach and can be readily found on making a post-mortem 

 examination. 



Symptoms of stomach worms are first manifest in the 

 lambs (Fig. 76). It is not until early summer that the disease 

 appears in the flock. The symptoms are not characteristic un- 

 less we consider an unthrifty, anaemic, weak, emaciated condi- 

 tion accompanied by diarrha?a during the summer months char- 

 acteristic of stomach-worm disease. The sick animals are unable 

 to keep lip with the flock, and they like to stand about in the 

 shade. They move slowly, the back is arched, the appetite poor, 

 the mucous membranes and skin are pale and the hind parts 

 soiled by the diarrhoeal discharge. More acute symptoms than 

 the above sometimes occur. The disease may last from a few 

 days to several weeks. A large percentage of the affected ani- 

 mals die. 

 17 



