2. CHRONIC METRITIS. PYOMETRA. 



Allied to acute metritis, and frequently following it as a sequel, 

 there occurs a chronic inflammation of the uterus, which is 

 characterized by suppuration of the uterine cavity, with more or 

 less accumulation of pus, constituting pyometra, or in case the 

 cervical canal of the uterus becomes completely occluded a large 

 volume of pus may be confined within the uterine cavity, to con- 

 stitute abscess of the uterus. 



Chronic metritis or pyometra may occur in any domestic ani- 

 mal, but has been observed chiefly in the mare, cow and bitch. It 

 may appear at almost any period in the life of the animal, and its 

 relation to parturition is variable. It occurs almost always in fe- 

 males which have previously bred, but the duration of time 

 elapsing between the last birth and the appearance of the disease 

 is not constant. In some cases, pyometra or chronic metritis 

 follows parturition after an interval of a few weeks, or there may 

 be a more or less definite acute metritis, which partially recovers, 

 to be continued somewhat indefinitely as a chronic, purulent in- 

 flammation. 



Anything which may lead to an infection of the uterus, and 

 permit it to continue for a long period of time, sufiices to estab- 

 lish the disease. Anything, therefore, which would debilitate 

 the organ or the general system, or which would favor or lead to 

 the introduction of micro-organisms into the uterus, would act as 

 a cause of the malady. Prominent among the recognizable 

 causes of this malady, are retained fetal membranes and any of 

 those causes which operate to bring about acute metritis, as de- 

 scribed in the preceding article. 



In many cases manipulations during dystokia appear to be the 

 essential source of an infection, which, though not sufiiciently 

 virulent to bring about an acute metritis, nevertheless induces a 

 chronic suppurative disease of the organ. 



a. Chronic Metritis in the Mare. Pyometra. 



Chronic metritis in the mare has not received that attention, 



from writers upon veterinary obstetrics or gynaecology, which 



its importance deserves. The affection is not at all rare in the 



mare, and often proves very obstinate when handled by the 



885 



