RET EXT mx OF THE J'WTJL EXVELOPES. 567 



such adhesion ; indeed, every obstetrist knows that at times there is 

 much difficulty in disuniting the cotyledons in the uterus. 



When the cervix uteri contracts rapidly after delivery, and the os is 

 consetjuently iirmly closed, the placenta, though non-adherent, will be 

 retained. 



Rueff mentions that the accident is especially frequent in certain 

 years when the herbage and forage is not good, and particularly when 

 the latter is mouldy ; it has long been known that these conditions 

 favour abortion. He also alludes to a popular belief in Germany, which 

 attributes this Zuriickhleihen der Nachcychurt, as it is termed, to allow- 

 ing the Calf to take the teat before the placenta has been expelled ; the 

 irritation of the udder so produced reacts sympathetically on the uterus, 

 which contracts at the cervix, and so retains the membranes. 



According to Baumoister, milking too soon, or giving cold water to 

 drink, is supposed to act in the same way. 



Numerous other causes have been mentioned as influencing this reten- 

 tion ; but they need not be noticed, as there is really no proof that they 

 do operate in this way. The accident occurs under all systems of 

 management, and all kinds of conditions ; it is, therefore, probable that 

 several causes may produce it, and that some of them are still obscure. 



Treat rnent. 



The treatment of placental retention appears always to have been a 

 subject on which diverse views and opinions have been held ; many 

 obstetrists maintaining that — with the Cow more particularly- -this 

 retention is never dangerous in itself, and that, unless there arise com- 

 plications, the removal of the fcttal membranes should in every case 

 be left to the efforts of Nature ; while others assert that there is great 

 risk in this retention, and that when it has exceeded two or three 

 days after the birth of the fcetus there is need for active interven- 

 tion. The experience of the majority of obstetrists will negative both 

 of these opinions ; for it is a matter of almost daily observation, that in 

 many instances the placenta remains without inconvenience in the 

 uterus for several days — six or eight — before it is spontaneously ex- 

 pelled ; while in other cases retention for the same period is marked by 

 more or less serious symptoms. This dilTerence undoubtedly depends 

 upon circumstances, the precise nature of which cannot always be fully 

 ascertained. Nor can positive rules be laid down as to when it is 

 time to interfere, or when abstention is the prudent course: — this 

 can only be learned by individual experience and the tact of the 

 practitioner. 



It may be remarked, however, that when parturition has been normal, 

 when the Cow does not appear to suffer pain or inconvenience, when 

 the " straining" is unfrequent and slight, the appetite good and lacta- 

 tion established, and particularly when, during a low or moderate 

 temperature a portion of the membranes protrude beyond the vulva, 

 then there is no great reason for interference until a week, or even more, 

 has elapsed. 



But if, on the contrary, the external temperature is high, if the labour 

 has been difficult, the genital organs irritated or abraded, and if fever, 

 restlessness, and suffering are noted, with strong and frequent strain- 

 ing, especially if there are foul-smelling discharges from the vagina, then 

 intervention is called for, no matter whether the time which has elapsed 

 since parturition is long or short. 



