SIGXS AND COURSE OF PAnTClUTION. 23$ 



1. Preliminari/ staijc ; 2. Dilatation of tlic os uteri; 3. Exptdsion of 

 thefntus; 4. Expulsion of tlic membranes. 



1. Preliiniiiarif Stage. — Various precursory signs announce the 

 approaching termination of pregnancy and the advent of labour. 

 These may be observed some hours, sometimes even for days, before 

 that event occurs. 



One of the most important signs is the enlargement and increased 

 sensibiUty of the mamma;, to which the excess of blood no longer 

 required in the uterus is directed. These glands become voluminous, 

 hard and tender ; and this phenomenon is more particularly remarkable 

 in those animals whose milk is not utilised after the young have been 

 weaned. The mammary glands then become soft, Haccid, and small, 

 and cease to secrete. In sucli animals as the Mare and VlwG, these 

 glands, ordinarily small and scarcely perceptible, before parturition 

 become so remarkably developed as to cause alarm in people who do 

 not understand the cause. With the Mare especially, the develop- 

 ment of the mammoD is sometimes so considerable, that the engorge- 

 ment extends along the inferior surface of the abdomen and simulates 

 oedema ; or it ascends between the thighs as high as the vulva as a 

 prominent ridge, while the skin in this region, if white, looks reddened. 

 At a later period, the teat yields a serous fluid on pressure, or this 

 constitutes a crust around it ; the fluid afterwards becomes somewhat 

 lactescent, and finally appears as the " colostrum " or first milk. 



Another premonitory sign is the tumefaction of the vulva, increase of 

 the space between the labia, which become soft and flabby, while their 

 lining membrane is reddened, and a viscid glairy mucus covers it. This 

 mucus, derived from the va^'inal lining membrane, soon becomes so 

 abundant that it is discharged in long filamentous streams, particularly 

 in the Cow, and soils the tail and hocks ; it is destined to lubricate 

 the genital passages, and faciUtate the extrusion of tlie foetus. 



With these changes the al)domen falls, or rather becomes more 

 pendent ; the croup looks hollow, as do the flanks, due to the relaxa- 

 tion of the broad ligaments. The spine, particularly in the lumbar 

 region, becomes more horizontal and rather inclines downwards, as if 

 yielding to tlie weight of the abdomen. The haunches appear to be 

 wider apart, and the gluteal muscles to subside, owing to the falling in 

 or modification of the sacro-sciatic, as well as the sub-sciatic, ligaments, 

 from serous infiltration. 



The animal walks sluggishly and unwillingly, and if grazing witli 

 others does not appear to care about following tliem. Sometimes, as 

 has been mentioned, there is swelling of tlie limbs, particularly the hind 

 ones. 



If very careful vaginal exploration be made at this time, it will bo 

 found that the cei-vix uteri has become a part of the uterine cavity and 

 is almost completely effaced, being reduced to merely a thin circular 

 ring ; its tissue is soft, and the os is slightly open in those animals 

 which have previously had young. 



As parturition draws nearer, these phenomena are more marked. 

 The animal also begins to be restless, and continually agitated ; if feed- 

 ing, it stops for some moments, as if listening to some sound only 

 audible to itself, or as if experiencing some strange internal sensation 

 for the first time, and which may certainly be the preparatory or com- 

 mencing contractions of the uterus. Not unfrequently the animal lies 

 down and gets up again, as if suffering from colic. Some are quite 



