130 



(3) Period of loss of flesh. — The sheep begin to become leaner at the 

 end of the third mouth after the immigration of the kirvae, or about 

 the beginning of January. The mahidy is then at its height. The 

 animal becomes gradually leaner; the mucous membranes and the skin 

 are bleached, and lose the yellow tinge. The temperature is variable 

 and is highest in either the morning or evening. Kespiration is feeble 

 and frequent. The appetite keeps up, and the feces present nothing 

 in particular except fluke eggs. The urine is nearly normal. The ani- 

 mals are listless and dejected, carry their heads low, and give way when 

 pressed on their backs. There are frequent abortions. Nursing ewes 

 have a clear, watery milk, very poor in nutritive elements. Their lambs 

 are weak and thin, and usually die unless they are put to another nurse. 

 The cedema becomes localized and increased in dependent parts. It is 

 dispelled by walking and comes again in rest. The space under the 

 jaws and along the trachea is a frequent seat of puffiness. This disap» 

 pears during rest and comes on during feeding. It is often absent 

 with adults in hot seasons. In the three weeks which follow the ani- 

 mals become still poorer despite abundant feeding, and there is gener 

 ally diarrhea, uidema, jaundice, and pain on pressure over the liver. 

 Either death occurs at this period, or the animals improve and enter the 

 next period. 



(4) Period of emigration of the flukes. — This is the period of convales- 

 cence and of spontaneous cure. All the symptoms grow less and finally 

 disappear, but the cure is never complete, the changes which have taken 

 place being irreparable. The recovery of affected sheep is exceptional. 



Duration of disease. — The flukes are said by some authors to remain 

 nine months in the liver, by others fifteen months. After this time they 

 make their way into the intestine and are ev^acuated with the excre- 

 ments. 



Thomas says that he has seen the sickness last six years, and Neu- 

 mann seems to coincide with Perroncito, that the flukes have little ten- 

 dency to quit their hosts. The question of reinfection of the same ani- 

 mal would leave it doubtful whether such long period of infection were 

 all due to the same parasites or to renewed generations of them. 



The duration of the disease, which, as a rule, is variable, depends en- 

 tirely on the degree of infection and the treatment, hygienic and me- 

 dicinal, which they receive. It ordinarily lasts about six months, but 

 exceptionally may have an extremely rapid course of a few days, death 

 being caused by an acute inflammation of the liver, set up by the para- 

 sites, and occurring in from seven to nine days after the first appear- 

 ance of the disease. Weakened by the fluke disease, the animals are 

 more susceptible to other maladies, and these may destroy them before 

 the primary disease has run its course. 



Diagnosis. — There is little difliculty in diagnosing liver-rot in the 

 stages at which it is first noticed if the flock-master sacrifices one of the 

 worst affected sheep. Although he may think that it hardly pays to 



