II. THE GENERAL INFECTIONS OF THE 

 GENITALIA OF MARES 



A. Diseases of the Ovaries 



1. Atretic Follicles 



The ovaries of healthy mares owe their chief volume to 

 the presence of a number of cysts, reaching a diameter of 

 one to two or more inches and containing colorless lymph. 

 They are virtually universal in young, healthy mares, and 

 at three to four years of age constitute more than seventy- 

 five per cent, of the ovarian volume. With the advent of old 

 age the cysts tend to disappear, the volume of the ovary de- 

 creases greatly, and the gland becomes distinctly senile. 

 The cysts have not been studied. Apparently they have no 

 pathologic significance, but on the contrary may serve an 

 important physiologic office. 



2. Nymphomania 



Nymphomania in mares bears some analogy to nympho- 

 mania in cows, but presents some very marked differences. 

 It has already been stated that nymphomania, as observed 

 in the cow, is due to a type of cystic degeneration of the 

 ovary, that no ovulation occurs, and that fertility is in abey- 

 ance. The disease designated nymphomania in the mare is 

 not so readily recognizable as being due to cystic degenera- 

 tion of the ovaries and its existence does not necessarily 

 cause sterility. 



Nymphomania is most commonly seen in mares which are 

 kept closely confined and are not bred. It is more rarely 

 observed in mares regularly worked and is well-nigh un- 

 known in those which are free. It is most commonly seen 

 in young or middle-aged mares, rarely in aged. It is quite 

 uncommon in mules, though in one instance 1 observed the 

 disease in so marked a degree as to render the otherwise 

 valuable animal worthless until castrated. 



