Common Diseases of Farm Animals Part 7

5. Give the causes and treatment of congestion and inflammation of the kidneys.

6. Give the causes of cyst.i.tis; symptoms; treatment.

7. Give the causes and treatment of retention of the urine.

CHAPTER VII

DISEASES OF THE GENERATIVE ORGANS

GENERAL DISCUSSION.--The study of the organs concerned with the reproduction of the species is essential in order to acquire a knowledge of their several functions. It is only through an understanding of these functions that we can prepare ourselves to correctly recognize, and successfully treat, or prevent, such diseases as may involve the organs of generation. A knowledge of the structure and function of the generative organs of the female is of greater importance from the standpoint of disease, than is a similar knowledge of the generative organs of the male.

The female is concerned with the complete reproductive process, which may be divided into four stages. These are _copulation_, _fecundation_, _gestation_ and _parturition_. The male is concerned only with _copulation_ and _fertilization_ of the ovum by the spermatozoa, while the female must protect and nourish the embryo and foetus until it has become sufficiently developed to live independently of the protection and nourishment afforded it within the womb. When the final stage of gestation is reached, birth or the act of parturition occurs.

GENITAL ORGANS OF THE FEMALE.--The female generative organs are the ovaries, fallopian tubules, uterus, v.a.g.i.n.a, v.u.l.v.a and mammary glands.

_The ovaries_ are a.n.a.logous to the t.e.s.t.i.c.l.es of the male. Their function is to secrete ova. This pair of glands is suspended from the superior region (sublumbar) of the abdominal cavity by folds of the lining membrane.

Leading from the ovaries, but connected with the surface of these glands only during the period of oestrum or heat, are the fallopian tubules. Their function is to carry the ovum from the ovaries to the uterus.

_The uterus or womb_ is a membranous sack situated in the sublumbar region and at the inlet to the pelvic cavity. It is held in position by numerous folds of the lining membrane of the abdominal cavity. We may divide the womb into three divisions, cornua, body and cervix.

The cornua or horns are long and cylindrical in shape. This portion of the womb is greatly developed in animals, like the sow and b.i.t.c.h, that give birth to several young. In the impregnated animal the wall of the cornua that contains one or several foetuses, and the body as well, becomes greatly thickened and the lining membrane more vascular.

The body is short in all domestic animals and connects the horns with the cervix or neck. The latter is represented by a narrow portion that projects backward into the v.a.g.i.n.a. In the cow the cervix is less prominent than in the mare and the tissue that forms it, quite firm. In the cow the opening in the cervix, the os, is very small.

_The v.a.g.i.n.a_ is a musculo-membranous ca.n.a.l that leads from the womb. In the mare and cow it is about one foot in length. Its function is to take part in copulation and parturition.

_The v.u.l.v.a_ is the external opening of the maternal pa.s.sages. It shows a vertical slit enclosed by lips, and interiorly it forms a pa.s.sage that is continuous with the v.a.g.i.n.a. This pa.s.sage is about six inches long in the larger animals. The different features that should be noted are the c.l.i.toris, a small erectile organ located at the inferior portion of the opening, the meatus urinaris, the external opening of the urethra, situated in a depression in the floor of the v.u.l.v.a, and the hymen, an incomplete membranous part.i.tion that may be found separating the v.u.l.v.a from the v.a.g.i.n.a.

_The mammary glands or udders_ secrete the milk that nourishes the young.

The glands vary in number. The mare has two, the cow four (Fig. 17), the ewe two and animals that give birth to several young, eight or more. Each gland is surmounted by a teat or nipple. The glandular tissue consists of caecal vesicles that form grape-like cl.u.s.ters around the milk tubules. The milk tubules from the different portions of the gland converge and form larger tubules that finally empty into small sinuses or reservoirs at the base of the teat. Leading from these sinuses are one or several milk ducts that open at the summit of the teat.

GENITAL ORGANS OF THE MALE.--The genital organs of the male are the t.e.s.t.i.c.l.es, the ducts or ca.n.a.ls leading from the t.e.s.t.i.c.l.es, the seminal vesicles, the glands lying along the urethra, and the p.e.n.i.s.

[Ill.u.s.tration: FIG. 17.--Photograph of model of udder of cow: milk duct; milk sinuses; and glandular tissue.]

_The t.e.s.t.i.c.l.es_ are the glandular organs that secrete the spermatozoa, the essential elements of the seminal fluid. These glands are lodged in the scrotal sack, situated between the two thighs.

Lying along the superior border of the t.e.s.t.i.c.l.e is a ma.s.s of ducts, the _epididymis_. The _vas deferens_ is the ca.n.a.l or duct that pa.s.ses from the epididymis to the region of the bladder and terminates near its neck by emptying into the seminal vesicles.

_The seminal vesicles_ are two membranous pouches situated just above the bladder. They act as receptacles for the seminal fluid. Two short ducts, the _ejaculatory_, carry the seminal fluid from the seminal vesicles to the urethra.

_The prostate gland_ is situated near the origin of the urethra. _Cowper's glands_ lie along the course of the urethra and near the origin of the p.e.n.i.s. These glands empty their secretions into the urethra and dilute the seminal fluid.

_The p.e.n.i.s_ is the male organ of copulation. It originates at the arch of the ischium and extends forward between the thighs. It may be divided into fixed and free portions. The free portion is lodged in the prepuce or sheath, but at the time of erection protrudes from it.

STERILITY, IMPOTENCY.--Fecundation does not always follow intercourse of the male and female. Impotency in the male and sterility in the female frequently occur.

_The causes_ are quite varied. A normal copulation may be impossible because of injuries to, and deformities of, the parts and tumor growths.

Deformed genital organs and obstructions of the os by growths and scar tissue are causes of sterility in the female.

Failure to breed is commonly caused by faulty methods of feeding and care.

Over-feeding and insufficient exercise may result in the body tissues becoming loaded with fat. This may cause a temporary sterility, but if persisted in, as is frequently the case in show animals, the sterility becomes permanent because of the genital glands failing to secrete ova and spermatozoa, or the lack of vitality of the male and female elements. Old age and debility from disease or poor care may induce loss of s.e.xual desire and an absence of, or weakened spermatozoa in, the seminal fluid. The refusal of the male to serve certain females is sometimes noted.

Tuberculosis may affect the ovaries and cause permanent sterility. In inflammation of the lining membrane of the womb and v.a.g.i.n.a, the secretions are abnormal and may collect in the womb and the pa.s.sages leading to it.

These secretions destroy the vitality of the spermatozoa, and this condition may be considered a common cause of sterility in the larger animals. Many vigorous young males are made impotent by excessive copulation. The excessive use of the male at any time may result in failure to impregnate a large percentage of the females that he serves.

Barren females do not become pregnant after frequent intercourse with the male. Young sterile females may not come in heat. Sometimes unnatural periods of heat are manifested, the animal coming in heat frequently or remaining in heat for a longer period than usual. This sometimes occurs in tuberculosis of the ovaries. In chronic inflammation of the maternal pa.s.sage there is more or less discharge from the v.u.l.v.a. Both s.e.xes may be overly fat or weakened and debilitated by disease. Deformity of the generative organs and growths may be found on making an examination.

Absence of, or lack of vitality of the spermatozoa may be determined by microscopic examination of the seminal fluid.

_The treatment_ is largely preventive. It is very important that breeding animals be kept in proper physical condition by avoiding the feeding of too heavy or too light a ration, and allowing them sufficient exercise. The male is more often affected by the latter cause than the female. This is because the average stockman does not consider exercise given under the right conditions an important factor in maintaining the vigor of the male.

Young males should not be given excessive intercourse with the female. Such practice is certain to seriously affect the potency of the animal. The excessive use of the stallion can be avoided by practising artificial impregnation of a part of the mares that he is called to serve. Sterility caused by growths and closure of the os may be corrected by an operation.

Chronic inflammation of the maternal pa.s.sages should be treated by irrigating the parts with a one per cent warm water solution of lysol, or liquor cresolis compound. The parts should be irrigated daily for as long a period as necessary. Fat animals should be subjected to a rigid diet and given plenty of exercise. Following this treatment a stimulating ration may be fed for the purpose of encouraging the s.e.xual desire. In weak and debilitated animals, the cause should first be removed and a proper ration fed. Cantharides and strychnine are the drugs most highly recommended for increasing the s.e.xual desire.

SIGNS OF PREGNANCY.--The signs which characterize pregnancy are numerous and varied. For convenience we may cla.s.sify the many signs of pregnancy under two heads, probable and positive. Under the head of probable signs, we may group the following symptoms of pregnancy: cessation of heat; changes in the animal's disposition; increase in the volume of the abdomen and tendency to put on fat. The positive signs are the change in the volume of the udder; the secretion of milk; the movement of the foetus and presence of the foetus in the womb, as determined by rectal examination or by the feel of the abdomen.

_The probable signs_ are not reliable, and should be considered only in connection with some positive sign. Persons who base their opinion of the condition of an animal that is supposed to be pregnant on probable signs, are frequently mistaken. It has frequently happened that animals whose condition was not at all certain have given birth to young, without giving rise to what may be termed characteristic probable signs.

The earliest probable symptom is the cessation of heat. In the large pregnant animals, irregular heat periods may occur, but in the majority of cases we may safely consider the animal impregnated if several heat periods are pa.s.sed over.

It has been generally observed that the disposition of the pregnant animal is changed. They become more quiet and less nervous and irritable. The tendency of pregnant animals to put on fat is frequently taken advantage of by the stockman, who may allow the boar to run with the herd during the latter period of fattening.

The increase in the volume of the abdomen may be considered a _positive_ sign of pregnancy in the small animals, but in the mare and cow it can not be depended on. Animals that are pregnant for the first time, do not show as great an increase in the volume of the abdomen as do animals that have gone through successive pregnant periods. The volume of the abdomen may vary greatly in the different individuals, and can not be depended on as a positive indication of pregnancy during the first two-thirds of the period of pregnancy in the larger domestic animals.

Comparatively early in pregnancy, the presence of a foetus can be determined by feeling the uterus through the wall of the r.e.c.t.u.m. In the small domestic animals the feeling of the abdomen gives the best results.

In the cow this method of diagnosis is practised during the latter periods of pregnancy. The examiner stands with his back toward the animal's head, and on the right side of the cow and the left side of the mare. The palm of the hand is applied against the abdominal wall, about eight or ten inches in front of the stifle and just below the flank. Moderate pressure is used, and if a hard, voluminous ma.s.s is felt, or if the foetus moves, it is a sure sign that the animal is pregnant. It is not uncommon for the foetus to show some movement in the morning, or after the animal drinks freely of cold water. The increase in the volume of the udder occurs at a comparatively early period in animals that are pregnant for the first time.

The secretion of milk and the dropping of the muscles of the quarters indicate that parturition is near. The Abderhalden test for determining whether or not an animal is pregnant is now practised.

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 part.i.tions 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 fas.h.i.+on, 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.