The Nodular Venereal Disease 293 



Should the heifer become pregnant at the first service, 

 the irritation may for a time abate slightly and slowly, but 

 the nodules remain prominent and approximately as numer- 

 ous as ever, and the clinical evidences of disease remain 

 essentially static, at one period apparently improved, at an- 

 other worse, until near the time for parturition, when the 

 vulvar mucosa becomes more reddened. A marked edema 

 (parturient edema) then appears: the nodules are covered 

 over and are no longer visible. Usually they may still be 

 felt upon careful palpation. In many cases of abortion the 

 edema of the vulvar mucosa is essentially the same as if 

 parturition had occurred. If parturition or abortion is fol- 

 lowed by retained placenta and chronic metritis or pyome- 

 tra, the nodules continue masked by the persisting edema 

 so long as serious uterine or vaginal disease continues. 

 Otherwise, with the gradual disappearance of the edema of 

 the mucosa, the nodules slowly come again into view. 



If the heifer fails to conceive at the first copulation, when 

 the next estrual period arrives and copulation occurs, 

 should the sterility be refractory, the symptoms tend to 

 increase, so that sterile heifers are quite generally among 

 the worst clinical cases in a herd. During the second and 

 third pregnancies the symptoms of the disease retain ap- 

 proximately the average intensity acquired during the first 

 pregnancy. Then the severity of the malady generally 

 abates. 



When the cow reaches eight to nine years of age and her 

 sixth or seventh pregnancy, the decrease in the intensity 

 of the disease generally becomes quite marked: the nod- 

 ules are fewer, less prominent, and more transparent; the 

 irritation and injection of the vaginal mucosa are definitely 

 decreased; and the muco-purulent discharge has largely 

 abated. With advancing age, the vulvar mucosa becomes 

 pale yellowish or bluish-yellow, the nodules disappear, and 

 the clinical evidences of the disease commonly vanish from 

 the vulva when the cow is twelve to fifteen years old. 



Such is a brief outline of the course of the malady as ob- 

 served in a majority of cases, but the course is vascillating 



