354 The Diseases of Animals 
not be used for food, nor placed where animals can eat 
it, unless it has been thoroughly cooked to kill the 
parasites. 
TRICHINE IN MEAT 
Trichinosis is a disease especially of pigs and man, 
caused by the invasion of the tissues of the body by a 
minute round-worm (Trichina spiralis), that bores its 
way to the different parts of the body, and then be- 
comes encysted. Fig. 54. Man usually contracts the 
disease by eating infested pork that has not been thor- 
oughly cooked. Trichinge in pork are 
invisible to the naked eye. When taken 
into the stomach, the eneysted worm is 
liberated, develops into an adult, and 
the females give birth to large numbers 
(ten to fifteen thousand) of embryo 
young. These young worms migrate, 
boring their way, or carried by the blood 
= and lymph, to distant parts of the body, 
Fig. 54. there developing the cyst stage. When 
Trichina spiralis . . 
encysted in lean these cysts are examined under a micro- 
meat. Magnified. scope, each is found to contain the 
small, cylindrical embryo worm, in a coiled or spiral 
position, from which it takes its Latin name. 
When meat infested with trichine is eaten, there 
follows, in the human subject, considerable irritation of 
the bowels, associated with diarrhea. This occurs in 
three to ten days after the meat has been eaten. 
During this period, the worms are multiplving in the 
digestive tract of the patient. Following this, there is 
LTT 
LCE 
Mm) 
