552 Distomatosis. 



and in the number of blood corpuscles may be demonstrated at 

 an early stage and even in slight cases (Schaper). 



In chronic cases, usually about the end of the autumn, 

 there is edema. Simultaneously with the gradual paling of 

 the mucous membranes there is edematous swelling of the con- 

 junctiva which forms a prominent ring around the cornea, and 

 causes swelling of the eyelid. Doughy swellings make their 

 appearance along the trachea, under the brisket, and on the 

 abdominal wall. By this time the dulness and weakness are 

 pronounced, the appetite is suppressed, rumination slow, the 

 wool dry and brittle and easily pulled out, and it even comes 

 out spontaneously at places thus making the fleece ragged. 

 Large numbers of fluke eggs can be found with the microscope 

 in the feces. By this time there is evidence of hydrothorax 

 and ascites. 



About the third month of infection, generally at the begin- 

 ning of winter, the wasting becomes more and more pro- 

 nounced and the edema and ascites are more evident. The 

 edema of the tracheal region decreases during the night and 

 reappears when the animals are at pasture during the day, 

 while the edema of other parts tends to decrease a little during 

 movement and to reappear with rest. In addition to edema- 

 tous swelling, Mergel observed abscesses on the neck and be- 

 low the flank which he believed were due to flukes. 



Coincident with the increasing emaciation, symptoms of 

 anemia and cachexia become more and more prominent. In 

 some cases there is diarrhea, the feces containing large num- 

 bers of eggs. The milk becomes watery and less nourishing, so 

 that the lambs are poorly developed and may even die. Some- 

 times there is fever. Finally, the animals die from complete 

 exhaustion. During the whole period of illness there is no 

 jaundice or, at the most, very slight evidence of it. 



More rol)ust and particularly older animals recover grad- 

 ually, especially after a moderate invasion, about the end of 

 the winter or in the early part of the spring. The edematous 

 swellings disappear, the appetite returns, and finally there is 

 apparent complete recovery. The tissue lesions in the liver 

 cannot be repaired and must eventually exercise a prejudicial 

 effect upon the nourishment of the animal. 



In goats the symptoms are very similar to those seen in 

 sheep and diseased animals often abort, or their progeny are 

 very weakly. 



Cattle, buffaloes and camels present similar symptoms, but 

 on account of their greater power of resistance the disease is 

 as a rule, less severe. In these animals, edematous swellings 

 along the course of the trachea and in the dewlap are more 

 rarely seen, but there may be digestive disorders such as an- 

 orexia, diarrhea, and tympanites and, in severe cases, anemia 

 and emaciation. A larger proportion of animals recover, and 



