2 DISEASES OF THE DOMESTIC ANIMALS 



causing irritation of the uterus; stone in the bladder or cystitis 

 causing constant straining; disease of the heart, as fatty heart, 

 leading to disturbances of the fetal circulation and death of the 

 fetus. 



4. Improper feeding, especially with ergotized, smutty or rusty 

 fodder. Also sudden change from dry to succulent diet, inducing 

 flatulence in cattle; deprivation of water, leading to indigestion; 

 constipation and straining; ice water; putrid water; frozen food. 



5. Diseases of the genital organs and of the fetus and mem- 

 branes. Tuberculosis of the ovaries and uterus. Interference 

 with the fetal circulation and mechanical obstruction in the um- 

 bilical cord, etc. 



6. Poisons, as powerful cathartics and diuretics, and those 

 taken accidentally or with the food, as ergot. 



7. Nervous shocks, as fright; and noisome odors, as from 

 slaughterhouse or proximity to animals with retained afterbirth. 



(B) Epizootic or Contagious Abortion. — Causes.— This 

 form of abortion is frequent among cows and is capable of being 

 communicated to sows, mares, ewes, goats, rabbits, guinea pigs. 

 When it once infects a barn it is difficult to eradicate. The disease 

 is either communicated by a special bacillus which enters the vagina 

 and womb and inhabits the space between the fetal membranes of 

 uterine walls, or apparently by several forms of bacilli — according 

 to various observers. In this country several forms of the colon 

 group have been described as the cause. The organism is found in 

 the uterine discharge and is conveyed to cows by the bull or by 

 floors, litter, walls, posts, tails or tongues soiled with vaginal dis- 

 charge from infected animals. Cows in advanced pregnancy carry 

 their young to full term, even though exposed to the infection. Of 

 animals aborting, some may remain sterile, some may abort per- 

 sistently, while others, after aborting two or three times, may re- 

 cover and go through normal pregnancies. 



Prevention of Accidental Abortion. — This embraces avoid- 



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