Course. Diagnosis. 553 



the disease may remain latent, altlioiigli the infestation may ho 

 severe (Wiegel). In exceptional eases, and especially among 

 yonng animals, death is due to utter exhaustion. According to 

 Vaelzen and Pease, many huffaloes are slaughtered in the East 

 Indies on account of distomatosis. 



Very occasionally, the disease runs the same course in 

 solipeds (ass) as in ruminants, wasting, anemia, dropsy, and 

 in some cases jaundice heing observed (Prietsch). 



In rabbits there is rapid wasting, hydrothorax, and as- 

 cites and, in occasional cases, swelling" and jaundice of the mu- 

 cous membranes (Braun). 



Course. Acute cases in which sheep die in seven to nine 

 days after the onset of symptoms from acute hepatitis, are 

 only rarely encountered (Bonvicini). In some cases, death is 

 quite sudden, possibly owing to embolism of young flukes in the 

 vessels of the brain (Gerlach) or to hemorrhage into the peri- 

 toneum following perforation of the capsule of the liver. With 

 such exceptions the disease tends to become chronic. The 

 course of the disease is divided by Gerlach and Ziindel into four 

 stages. (1) The stage of traumatic hepatitis which begins soon 

 after infection, lasts four to thirteen weeks, and is character- 

 ized by slight sjanptoms of fever, digestive disorders, and en- 

 largement and sensitiveness of the liver. (2) The stage of 

 chlorosis. This sets in in the autumn, lasts six to twelve weeks, 

 and is characterized by symptoms of anemia. (3) The stage 

 of wasting as a rule sets in about four months after infection 

 during the winter months. In this stage emaciation and drop- 

 sy are pronounced and deaths are frequent. (4) The migra- 

 tion of the flukes occurs in the spring, a])out May or June (Ger- 

 lach). During this stage, symptoms disappear* and there may 

 be temporary or permanent improvement. The investigations 

 of Friedberger and Schaper have shown that this division into 

 stages is applicable to a certain extent in cases where there are 

 extensive outbreaks because there are a number of animals se- 

 verely and simultaneously affected. Such outbreaks generally 

 occur in the summer and autumn. 



In most cases the stages cannot be marked off from each 

 other and the series of symptoms described above cannot be 

 followed out. The eggs of the parasites may be passed out and 

 the parasites themselves migrate at any time. There is great 

 variation in the duration of the disease. In some cases where 

 the infestation is severe, it may last only three months, and in 

 another case it may extend to a year or more. 



Diagnosis. Obvious symptoms are seen in advanced cases 

 only, and more or less closely resemble those due to other 

 causes (tapeworms, gastric strongyles, etc.). The edematous 

 infiltration cannot be considered as characteristic of liver rot. 

 As a rule, no difficulty is experienced in practice, in arriving 



