TRICHINOUS INFECTION OF MAN AND ANIMALS. 169 



stage of parasitic invasion. A diarrhoea soon followed, attended 

 with more or less fever, restlessness, and prostration, but these sj'inp- 

 toms were often variable both in time and degree, according to the 

 susceptibility of the animal. In young pigs, the gastro-intestinal 

 irritation not infrequently proved fatal within ten days after feeding 

 them with infected meat. 



The second phase of the malad}' is indicated by rheumatic pains 

 and soreness of the muscles, which appear in the second or third 

 week, when the larval trichinae commence their migration through the 

 tissues. These symptoms come on gradually, as the others disap- 

 pear, and thus vary somewhat in character, according to the group 

 of muscles invaded by the parasites. 



In this stage, hogs manifest a restless disposition, lying down and 

 getting up again as if to change positions for comfort. They walk 

 with a tottering gait, are stiff and unstead}' in all their motions. 

 Hence the reason why the}' seem to prefer to lie stretched out, as if 

 to rest their wear}' limbs, from which position such affected animals 

 often require help to rise. 



When the muscles of mastication and deglutition are invaded, the 

 hog manifests great difficulty in eating and it is often impossible for it 

 to swallow even liquid food. Symptoms of lock-jaw therefore fre- 

 quently supervene and thus become a serious complication, especially 

 if the throat and the respiratory muscles are also affected. In such 

 cases, the breathing is labored, and there is more or less wheezing. 

 The voice of the animal, Gerlach noticed in several instances to 

 change very materially, and it even became aphonic from the inva- 

 sion of these parasites. Consequently, such afflicted animals have 

 no power to squeal, even when disturbed. 



The tongue and under lip are frequently swollen, and sometimes 

 the cheeks and the muscles of the neck are also involved, giving a 

 general odematous appearance about the head. The eyes become 

 suffused with tears, and the conjunctiva wears a reddened hue for 

 several days. 



With such a group of symptoms present, a shoat must lose condi- 

 tion rapidly and thus become very weak and emaciated in a short 

 time. But the symptoms of experimental cases of trichinization, ac- 

 cording to Gerlach, are quite variable, depending largely upon the 

 quantity of infected meat that had been administered at one time. 



Where the quantity was small, the animal seemed to suffer but lit- 

 tle from its effects, and yet after repeated trials he found the entire 



