HYGIENE OF PREGNANT ANIMALS.—Pregnant animals that are confined in a pasture that is free from injurious weeds and not too rough or hilly, and where the animals have access to clean water and the necessary shelter, seldom suffer from an abnormal birth. Here they live under the most favorable conditions for taking exercise, securing a suitable diet and avoiding injury. It may not be possible in managing breeding animals to provide such surroundings at all times, but we should observe every possible hygienic precaution, especially if the animal has reached the later periods of pregnancy.
All pregnant animals are inclined to be lazy, but, if permitted, will take the necessary exercise. Pregnant mares are usually worked. Such exercise does no harm, providing the work is not hard or of an unusual character. Cows are usually subject to more natural conditions than other domestic animals.
Protecting pregnant animals against injuries resulting from crowding, slipping and fighting is an important part of their care. Injuries from crowding together in the sleeping quarters and about feeding-troughs, or through doors and climbing over low partitions are common causes of injury in pregnant sows. Crowding together in the stable or yard, or through doorways, fighting, and slipping on floors, or icy places sometimes results in injury. It is rare, however, for cows to abort from an injury, but parturition may not be completely free from disagreeable complications. Under the conditions mentioned retention of the fetal membranes is common.
Ewes frequently suffer from too close confinement during late winter. Sows are often subject to the most unhygienic conditions. This is shown in the heavy death-rate in sows and pigs. During the late winter and early spring the conditions may be such as not to permit of exercise. Stormy, snowy, muddy weather is common at this season of the year. Persons caring for ewes and sows should see that they take sufficient exercise. It may be necessary to drive them about for a short time each day. At such times it may be advisable to give them a laxative dose of oil, or give a laxative with the feed. When there is any indication of constipation, this should be practised.
Pregnant animals should be fed carefully. We may feed animals that are not in this condition in a careless fashion, but if pregnant, over-feeding, the feeding of a fattening ration, or spoiled feed, and sudden changes in the feed can not be practised with any degree of safety. A bulky ration of dry feed and drinking impure, or too little, water may cause constipation, acute indigestion and abortion. The ration fed should contain the necessary inorganic and organic elements for the building up of the body tissues of the foetus.
At the end of the parturition period, separate quarters should be provided. The mare or cow should be given a comfortable clean stall away from the other animals. The ewe should be provided with a warm room if the weather is cold. It is always best to give the sow a separate pen that is dry and clean, and away from the other animals. All danger from injury to the mother and young should be guarded against.
ABORTION.—The expulsion of the foetus at any time during the period of gestation, when it is not sufficiently developed to live independently of the mother, is termed abortion. Abortion may be either accidental or infectious. Accidental abortion is more commonly met with in the mare and sow than the infectious form. In ruminants the opposite holds true.
The causes of accidental abortion are faulty methods of feeding and care. Injuries, acute indigestion, mouldy, spoiled feeds, chilling resulting from exposure and drinking ice-cold water, nervousness brought on by fright, or excitement and general diseases are the common causes of abortion.
Infectious abortion is most common in cows. Other domestic animals that may be affected are the mare, sow and ewe.
It is caused by a specific germ. The Bacillus abortus of Bang is the cause of abortion in cows, but the specific germ that produces abortion in other species of animals has not been proven. In this country, Keer, Good, Giltner and others have proven that the Bang bacillus of abortion is infectious for other species of animals, and outbreaks of this disease have been said to occur among breeding ewes pastured and fed on infected premises. Its infectiousness for the females of other species has never been proven in natural outbreaks.