Cystic Degeneration of the Corpus Luteum 417 



ovulation. Sometimes ovulation and estrum are regular 

 and the duration of the disease is approximately the same 

 as in the normal cycle of estrum. In many cases, however, 

 cystic degeneration interrupts the normal estrual cycle so 

 that, if the degeneration is very rapid, the animal may be in 

 estrum again in eight to fifteen days, or it may be delayed 

 until thirty days or more. So far as I have been able to 

 judge by clinical study, it is the principal cause of irregu- 

 larity in the estrual cycle. Not only does it interrupt the 

 estrual cycle in the non-pregnant animal, but sometimes it 

 involves the pregnant animal, bringing about a recurrence 

 of estrum in spite of the presence of a normally developing 

 fetus. 



The prognosis of cystic degeneration of the corpus luteum 

 is unfavorable because, so far as at present understood, it 

 is largely dependent upon an irremediable infection in the 

 oviduct. If it involves only one ovary and oviduct, the prog- 

 nosis may be good because of the freedom of the other side, 

 but unfortunately cystic degeneration of the corpus luteum 

 and tubal infection are usually bilateral. Some cases re- 

 cover, but when it is once clearly recognizable one needs to 

 give a very guarded or unfavorable prognosis. 



There is no well-established method for handling cystic 

 degeneration of the corpus luteum which promises favorable 

 results. It has been the habit with many, especially in the 

 beginning of the work with sterility in cattle, to dislodge the 

 cystic corpus luteum, but when one views the question from 

 the standpoint of the etiology as interpreted above, it would 

 appear that tampering with such a condition is not usually 

 justifiable. If one dislodges the corpus luteum, there is a 

 new wound which offers an excellent avenue for invasion 

 from the oviduct. It may be thoroughly justifiable to dis- 

 lodge the corpus luteum, or at least to compress it sufficiently 

 to rupture the cyst in its center in order to make a diagnosis. 

 When the diagnosis has been made, however, and the veteri- 

 narian is aware that the difficulty is due to this cystic de- 

 generation and understands that it is almost certainly ac- 

 companied by salpingitis, the more prudent course in the 

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