40 VETERINARY OBSTETRICS. 
In the Cow; there are two distinct umbilical veins, 
and these only unite after they enter the abdomen of 
the foetus. 
While these structures are being developed in the 
uterus of the parent, certain changes are visible 
externally, by which we are enabled to say whether the 
animal is pregnant or not. 
Symptoms of Pregnancy and Parturition. 
The first, in the Mare and Cow, is the absence of 
the period of cestrum. This rule, however, has several 
exceptions, as it often happens that this period may be 
absent, or present unnoticed, and still the animal 
remain non-pregnant. On the other hand, the animal 
may show all the symptoms, except the menstrual 
discharge from the vulva, and may at this season allow 
copulation with the male, while being in a pregnant 
condition, and may be again impregnated. 
The Mare soon becomes altered in general tem- 
perament and behaviour. If used for harness purposes, 
she becomes dull, lazy, and somewhat difficult to drive, 
and for the first three months after impregnation has a 
tendency to put on condition. The abdomen becomes 
pendulous, a well marked hollow being seen at the 
flank, 
In the Mare, the mamme often secrete a white, 
thin fluid, for a few days, about nine months after 
impregnation; afterwards, this secretion stops, the 
gland resumes its normal condition, but may again fill, 
and secrete this fluid, at varying intervals throughout 
pregnancy. 
