420 Veterinary Medicine. 



maturity only reached in intestines of suitable warm-blooded animal, though 

 passes alive through the body of fish ; expelled in faces mature worm per- 

 ishes in water, embryos live ; ovigerous female found in gland ducts of in- 

 testinal mucosa, mesentery and mesenteric glands. Embryo migrates in 

 blood but mainly in lymph vessels. I/arvse set free in stomach from trichi- 

 nous meat in 5 to 20 hours, become mature in i to 3 days more ; larva found 

 in diaphragm seventh day, in muscles generally the thirteenth ; also in 

 serosae. One female has 15,000 ova. Curling in 8 or spiral become covered by 

 fibro-cellular cyst 0.4 mm. long. Host being eaten the freed larvte repeat 

 the above for new generation ; or host living they finally die and cyst is cal- 

 cified. Successive hosts in chain : Pig and rodent, rat, mouse ; dog and hog 

 about abattoirs ; man and pig ; rat, pig and man. Infested chopping block, 

 sausage cases, under-done pork. Trichinosis in different countries. Symp- 

 toms : Intestinal for 15 days, colic, tenderness, anorexia, nausea, diarrhoea, 

 weariness. Muscular tenth to fortieth day, muscles swollen, tender, stiff, 

 cramps, unlike rheumatism, spares joints and tendon sheaths, oedema, 

 stertor, skin eruption, hyperthermia, albuminuria. In swine, usually pass 

 unnoticed. Diagnosis: Trichina harpoon, antiseptic incision, Duchenne's 

 punch. Treatment : First by emesis ; stomach-pump or tube ; wash stom- 

 ach with glycerine ; whisky, alcohol, vermifuge, purgative. Prevention in 

 Swine : Do not give uncooked meat, unboiled water, kill vermin, boil swill ; 

 avoid drainage from other herds, abattoirs, rendering works, sewers, privies ; 

 prevent swine running at large where they can get human excrement ; burn, 

 etc., all infested carcases, hogs, mice, rats, etc. Prevention in Man : Erad- 

 icate from swine ; thoroughly cook all flesh ; freeze throughout to 14° C. ; 

 salt thoroughly for one month ; examine microscopically all pork ; technic 

 of examination ; organisms mistaken for trichinae. Classification of trichi- 

 nous pork. 



Definition. The invasion of a living organism, and especially 

 the alimentary canal and the voluntary muscles by the trichina 

 spiralis. 



Stages. Forms. The trichina attacking any host, invades 

 first the alimentary canal — intestinal trichinosis — in which the 

 sexually mature trichinae live in the intestines and propagate their 

 kind — and second they enter the intestinal walls, striated muscles 

 and other solid ti.ssues in which the larvae encyst themselves and 

 remain enclosed without further development — muscular trichi- 

 nosis. These two forms are in a sense one continuous invasion, 

 the mature trichina in the intestine perishing after they have 

 given birth to their young, and the young or larvae boring their 

 way into the muscular tissues to remain there but partially de- 

 veloped and a.sexual. 



Animals Susceptible. The known hosts of trichina spiralis are 

 man, pig, brown rat, mouse, dog, and less frequently badger, cat. 



