172 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



stant excitement of the nervous system, will strongly conduce to 

 abortion. How much more so if the food is lacking in the mineral 

 matter, and especially the phosphates necessary for the building up 

 of the body of both dam and offspring, to say nothing of that drained 

 off in every milking. This state of things is present in many old 

 dairy farms, from which the mineral matters of the surface soil have 

 been sold off in the milk or cheese for generations and no return 

 has been made in food or manure purchased. Here is the craving 

 of an imperative need, and if it is not supplied the health of the 

 cow suffers and the life of the fetus may be sacrificed. 



Among other causes of abortion must be named the death or the 

 various illnesses of the fetus. There is in addition a series of diseases 

 of the mucous membrane of the womb, and of the fetal membranes 

 which interfere with the supply of blood to the fetus or change its 

 quality so that death is the natural result, followed by abortion. 



CAUSE OF CONTAGIOUS ABORTION. 



"While any one of the above conditions may concur with the con- 

 tagious principle in precipitating an epizootic of abortion, yet it is 

 only by reason ofthe contagium that the disease can be indefinitely 

 perpetuated and transferred from herd to herd. When an aborting 

 cow is placed in a herd that has hitherto been healthy, and shortly 

 afterwards miscarriage becomes prevalent in that herd and continues 

 year after year, in spite of the fact that all the other conditions of 

 life in that herd remain the same as before, it is manifest that the 

 result is due to contagion. When a bull, living in a healthy herd, 

 has been allowed to serve an aborting cow, or a cow from an aborting 

 herd, and when the members of his own herd subsequently served by 

 him abort in considerable numbers, contagion may be safely inferred. 

 Mere living in the same pasture or building does not convey the in- 

 fection. Cows brought into the aborting herd in advanced preg- 

 nancy carry their calves to the full time. But cows served by the 

 infected bull, or that have had the infection conveyed by the tongue 

 or tail of other animals, or by their own, or that have had the exter- 

 nal genitals brought in contact with wall, fence, rubbing post, litter, 

 or floor previously soiled by the infected animals, will be liable to 

 suffer. Galtier finds that the virus from the aborting cow causes 

 abortions in the sow, ewe, goat, rabbit, and guinea pig, and that if 

 it has been intensified by passing through either of the two last- 

 named animals it will affect also the mare, bitch, and cat. 



It does not appear that it is always the same organism which 

 causes contagious abortion. In France, Nocard found in the abort- 

 ing membranes and the mucous membrane cocci, or globular bodies, 

 singly or in chains, and a very delicate rod-shaped organism by 

 which the disease was propagated and which survived in the womb 

 through the interval between successive pregnancies. The Scottish 

 commission found as many as five separate kinds of bacteria. Bang, 

 in Denmark, found a very delicate rod-shaped organism showing its 

 most active growth at two different depths in nutrient gelatin, and 

 which produced abortion in twenty-one days when inoculated on the 

 susceptible pregnant cow. In America, Chester, of Delaware, and 



