Co7itrol and Eradicafio?! 489 



the mother may be differentiated from infectious abortion proper 

 by the symptoms in the pregnant mare. 



It has been claimed that infectious abortion can be differenti- 

 ated from other types by the dark, dirt3^ grayish or brownish 

 color of the chorion and the abundant dirty exudate upon its 

 surface. If a fetus, dead from other causes, remains in the uterus 

 until decomposition of the membranes begins, we know of no 

 good reason why the appearances might not be the same as those 

 described as characteristic of the infectious di.sease. Bacterio- 

 logic differentiation is not yet available. 



When an abortion occurs in a stable, unless it can clearly and 

 safely be attributed to other causes, a tenative diagnosis of in- 

 fectious abortion should be made and the case handled accordingly. 



It is very difficult to prevent the introduction of the disease 

 into a stable of pregnant mares, when the malady is prevalent in 

 a neighborhood. When abortion among mares exists upon a 

 farm during a season of the year when the animals are habitually 

 out in the fields, and the aborting mares are separated from the 

 healthy ones of an adjoining farm simply by a fence, the trans- 

 mission of the disease from the one farm to the other is well-nigh 

 inevitable and can only be guarded against by providing a neutral 

 territory between the infected and the non-infected mares. 



It is also essential that owners of pregnant mares should guard 

 them zealously against infection through the introduction of 

 mares from stables where the disease exists. If it becomes neces- 

 sary or advisable to purchase new mares and bring them upon 

 the farm, and it is not certain that they are free from the infec- 

 tion, they should be isolated for an ample period of time before 

 allowing them to come in contact with the pregnant animals. 

 If any well-grounded suspicion of the animal exists, she should 

 be thoroughly disinfected, perhaps even subjected to a bath in 

 disinfectants, which would include the entire body, and a special 

 disinfection of the vulva and vagina. 



It is highly dangerous, when abortion is disseminated over a 

 territory, to permit outside animals to come into the stable or 

 enclosure where pregnant animals are kept. We have known 

 instances where a mare, which had recently aborted, was driven 

 into the barn-yard of a neighboring farm where the disease did 

 not exist, and, although the stay of the infected mare was of short 



