28 VETERINARY OBSTETRICS. 
In the Mare, about eighteen months to two and a 
half or three years, but where attention to improvement 
of breed is paid, the Mares should not become mothers 
till they are four years of age, as the parent and 
offspring are both more valuable. 
Certain characteristic changes take place in the 
female on the appearance of puberty. These changes 
remain for a short time only, then disappear, to appear 
again with more or less regularity throughout the 
whole fertile period of the animal’s life. When these 
conditions mentioned are present, they indicate what 
is known as the period of cestrum, rut, or heat. 
Some of these changes can be recognized exter- 
nally, others can not. In the Cow, we notice an 
irregularity in feeding, partial loss of appetite at this 
period; roaring occasionally; pulse irritable and 
accelerated ; temperature slightly elevated, which may 
be from one to two degrees Fahrenheit. If the Cow 
be giving milk, the supply will be decreased, and in the 
Mare, which has never been in milk, the mammary 
glands become enlarged, congested, and sometimes 
secrete a fluid very much resembling healthy milk. 
The mucous-membrane of the vulva and vagina, in all 
animals, becomes injected, and red in color. The 
clitoris is enlarged, and frequent movements of that 
organ take place. There is also a discharge from the 
vulva of a gelatinous looking fluid, believed to come 
from the walls of the vulva, vagina and uterus, and in 
some animals, from the glands of Gertner, already 
described. If the animal be at liberty, there seems to 
be a natural desire for her to seek the opposite sex. 
