8 BULLETIN 106, U. S. DEPARTMENT OF AGRICULTURE. 



covered with masses of stringy, semiopaque mucus, or there may be 

 seen small opaque flakes of muco-pus resting upon the mucosa. 



The nodules now multiply with astonishing rapidity. Their 

 arrangement in parallel longitudinal rows becomes well marked, the 

 nodules being crowded into close contact with each other upon the 

 summits of the swollen, hypertrophied mucous ruga?. The nodules 

 frequently lose their transparency and assume a deep-red color, and 

 the malady assumes in eveiy way a more decisive clinical aspect of 

 important disease. Even then, however, it is not noticeable in so 

 far as the general health of the heifer is concerned. 



The intensity of the symptoms increases for a few days, remains 

 static for a time, and then tends to recede slightly, but the betterment 

 makes no appreciable approach to the status which had been main- 

 tained prior to copulation — a fact which emphasizes strongly its 

 essentially venereal character. 



Should the heifer become pregnant at the first service, the irritation 

 may abate slightly and slowly for a time, but the nodules remain 

 prominent and approximately as numerous as ever, and the clinical 

 evidences of disease remain essentially static, at one period apparently 

 improved, at another 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. Should 

 parturition or abortion be followed by retained placenta and 

 chronic metritis or pyometra, the nodules continue masked by the 

 persisting edema so long as serious uterine disease continues. Other- 

 wise, 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 of the disease in a herd. 

 The symptoms of the disease retain approximately the average 

 intensity acquired during the first pregnancy through the second and 

 third pregnancies, when the severity of the malady gradually abates. 



When the cow reaches 8 to 9 years of age, and her sixth or seventh 

 pregnancy, the decrease in the intensity of the disease generally 

 becomes quite marked, the nodules are fewer, less prominent, and 

 more transparent, the irritation and injection of the vaginal mucosa 

 is 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 when the cow has reached 

 the age of 12 to 15 years. 



