122 VETERINARY PARASITOLOGY 
symptoms noticeable are those of enteritis. There may 
be anorexia, fever, thirst, grinding of the teeth, with 
tucked-up flanks and arching of the back. Chronic 
diarrhcea then sets in. About the tenth day these 
symptoms diminish and give way to muscular symptoms. 
The animal is stiff and has difficulty in walking. The 
muscles are sore to touch, and the pig usually remains 
in the recumbent position. The animal may now re- 
cover or become dropsical and eventually die. 
INFECTION, ETC.—Infection takes place in the pig 
from ingestion of trichinosed flesh, such as that of rats, 
which are frequently affected, or from devouring the 
excreta of animals containing Trichina in some stage of 
their life-history. Probably the pigs infect the rats, and 
vice versa, and so the existence of the disease is main- 
tained. In Germany, America, Holland, Denmark, and 
Sweden, and particularly in Russia, trichinosis in man 
is not rare, owing to the practice of eating only partially 
cooked pork. 
VitaLity.—Boiling affected pork for fifteen minutes 
per pound weight is considered safe, and experiment has 
shown the Trichina to be destroyed by this means. 
Roasting, if complete, is sufficient to destroy the 
parasites. 
Salting and smoking are not reliable. 
Putrefaction has little influence on their vitality, and 
after four months some Trichine may yet be alive. 
PARASITES AFFECTING THE EYE. 
Numerous parasites may affect the eyelids. Among 
these are Acari, Demodectes, and the Pediculide. 
Besides these, various Diptera attack theexterior of the 
eye, especially the nasal canthus. 
Filaria Pellucida.—There is some doubt as to whether 
this worm may not be an undeveloped stage of Filaria 
