FAKMKKs' INSTITUTES. SO'-j 



edges are .smooth and lyliiidrical in shape and contain liool^ed t'nibryos. 

 They average about one two hundred and fiftieth of an Ineli in lengtli. 



Source of Infection.— The eggs are passed out witli tlie faeces and 

 boconie scattered aroiuid the pastures, aroun<l tlie pt-ns and mixed witli 

 the manure. AVhite grubs, which are very plentiful around dung liills. 

 eat the eggs and become infested with the larvae and act as intermediate 

 hosts. Hogs eating these grubs are in turn infested with the adult worms. 

 Hog.s will search diligently for these in loose rich soil. Some seasons they 

 are more common than in others, and the extent of infection to a certain 

 extent will vary according to the locality and the season of the year. 



Symptoms.— When a nundjer of these thorn-headed worms arc present 

 in the intestines, tliey greatly irritate the lining membrane and may cause 

 serious symptoms, especially in young pigs. Where the worm attaches 

 itself there is a small inflamed area of tissue a quarter of an inch or 

 more in diameter. Sometimes the lesions are no larger tlian a pin head. 

 The inflamed areas are circular in outline and depressed in the center. 

 where the rostellum is imbedded and the mucous memljrane is tiiiclcened. 

 firm and reddened. The proboscis may be buried more deeply tlian the 

 mticous coat and involve the muscular coat as well. Instances wliere the 

 wall of the intestine was peiforated liave l)een reported. 



The symptoms as described by observers are loss of appetite, constiita- 

 tion, diarrhoea, restlessness, general emaciation, weakness of tlie loins, 

 and. in very young pigs, convulsions and spasms. The majority of cases 

 present no symi)toms at all and the worms are only found at slaughtering. 



Treatment.— It is not best to allow hogs to root arovmd old straw 

 stacks and manm-e heaps. The best treatment for the thorn-headed 

 worms is tlie turpentine treatment, as recommended for the ascaride. 

 Tt should be given on three <-onsecutive days. All vermifuges if followed 

 by a purgative are ettective. Better results ai'e secttred if all food is with- 

 held for about twelve hours before administering a remedy. This can be 

 easily done l>y keeping tlie pigs in tlie pen at night and dosing tliciu in the 

 morning. 



The Tin Worm. — The pin worm, Oesoiiliagostoma deiitatuiii. is <iuite 

 small. It inhabits the caecum and colon of hogs, and may be found in 

 large numbers in tliis part of the intestine. Unless looked for c.-irefuUy. 

 it is not noticed. 



Descrii»tion.— The iiody is white or brownish in color, stiraiglit and 

 TKiinted at both ends. The male is half an inch in lengtli; the female a 

 little longer. The mouth is circular, and surrounded by a ri<lge on wliicli 

 are several jiapillae. The caudal pouch of the male is bell-shaped and 

 rounded, witli a faintly marked middle lobe. That ttf tlie female is 

 pointed. Tlie vulva is situated in front of the anus and surrounded by a 

 raisetl ring. 



I-ittle is known of its life history. It causes but litlh' if any digestive 

 disturlianci's. Irritation t<» the walls of the caecuiii <>i- ciiinii does not 



