DISEASES OF THE GENERATIVE ORGANS. 183 
of stone in the kidneys, uterus, bladder, or urethra may induce so 
much sympathetic disorder in the womb as to induce abortion. In 
exceptional cases wherein mares come in heat during gestation, service 
by the stallion may cause abortion. Blows or pressure on the abdo- 
men, rapid driving or riding of the pregnant mare, especially if she 
is soft and out of condition from idleness, the brutal use of the spur 
or whip, and the jolting and straining of travel by rail or boat are 
prolific causes. Bleeding the pregnant mare, a painful surgical op- 
eration, and the throwing and constraint resorted to for an operation 
are other causes. Traveling on heavy, muddy roads, slips and falls 
on ice, and jumping must be added. The stimulation of the abdom- 
inal organs by a full drink of iced water may precipitate a miscar- 
riage, as may exposure to a cold rainstorm or a very cold night after a 
warm day. Irritant poisons that act on the urinary or generative 
organs, such as Spanish flies, rue, savin, tansy, cotton-root bark, ergot 
of rye or other grasses, the smut of maize and other grain, and 
various fungi in musty fodder are additional causes. Frosted or 
indigestible feed, and, above all, green succulent vegetables in a 
frozen state, have proved effective factors, and filthy, stagnant water 
is dangerous. Low condition in the dam and plethora have in oppo- 
site ways caused abortion, and ‘hot, relaxing stables and lack of 
exercise strongly conduce to it. The exhaustion of the sire by too 
frequent service, entailing debility of the offspring and disease of 
the fetus or of its envelopes, must be recognized as a further cause. 
The symptoms vary mainly according as the abortion is early or 
late in pregnancy. In the first month or two of pregnancy the mare 
may miscarry without observable symptoms, and the fact appears 
only by her coming in heat. If more closely observed a small clot 
of blood may be found behind her, in which a careful search reveals 
the rudiments of the foal. If the occurrence is somewhat later in 
gestation, there will be some general disturbance, loss of appetite, 
neighing, and straining, and the small body of the fetus is expelled, 
enveloped in its membranes. Abortions during the later stages of 
pregnancy are attended with greater constitutional disturbance, and 
the process resembles normal parturition, with the aggravation that 
more effort and straining is requisite to force the fetus through the 
comparatively undilatable mouth of the womb. There is the swelling 
of the vulva, with mucus or even bloody discharge; the abdomen 
droops, the flanks fall in, the udder fills, the mare looks at her flanks, 
paws with the fore feet and kicks with the hind, switches the tail, 
moves around uneasily, lies down and rises, strains, and, as in natural 
foaling, expels first mucus and blood, then the waters, and finally the 
fetus. This may occupy an hour or two, or it may be prolonged for 
a day or more, the symptoms subsiding for a time, only to reappear 
-with renewed energy. If there is malpresentation of the fetus it will 
