Special Report on Diseases of Cattle Part 14

HEMOPTYSIS.

Hemoptysis is a term used to signify bleeding from the lungs. The trouble may result from a previous congestion of the lungs or from a breaking down of the lung substance, or from specific disorders.

Bleeding from the lungs comes from both nostrils and from the mouth. The blood is bright red, frothy, and accompanied with a cough, the flow being somewhat profuse and intermingled with mucus. It may cease of its own accord. Internally hemostatics are indicated, and locally over the sides cold applications have a tendency to check the hemorrhage. A drench of 1-1/2 drams of gallic acid dissolved in a pint of water should be given.

ABSCESS OF THE LUNG.

Abscesses of the lung sometimes form during the course of or subsequent to tuberculosis or other diseases. An animal affected with abscess of the lung usually has a protracted, feeble cough and a general appearance of emaciation and anemia. The pulse is feeble and the breath foul. An offensive discharge from the lungs frequently occurs. Percussion and auscultation aid in making a diagnosis in this condition. The appet.i.te is poor. Such animals go from bad to worse, and their prompt destruction would, as a rule, be to the interest of the owner.

HYDROTHORAX.

Hydrothorax, or dropsy of the chest, is not a disease in itself, but is simply a condition in which an effusion takes place in the chest cavity, and is the result or effect of some disease, mostly pleurisy. It can be easily diagnosed by physical signs. A loss of the respiratory murmur will be noticed on auscultation, and on percussion dullness or flatness on a line as high as the effusion has taken place. When a large amount of effusion is present, tapping with the trocar and cannula is generally resorted to. The proper method of performing this operation will be found under the head of "Pleurisy."

PNEUMOTHORAX.

An acc.u.mulation of gas in the pleural sac is known as pneumothorax. The presence of air may result from either an injury of the lung or a wound communicating from the exterior. The indications for treatment are to remove any foreign body that may have penetrated, to exclude the further entrance of the air into the cavity by the closure of the external opening, and to employ antiseptics and adhesive dressings. The air already in the cavity will in most cases be absorbed.

VERMINOUS BRONCHITIS.

This is a disease that sometimes attacks young cattle when pastured in low-lying meadows near rivers subject to flood. It is caused by a small worm, _Strongylus micrurus_, which lodges in large numbers in the trachea and bronchial tubes, giving rise to considerable irritation of the air pa.s.sages and inflammation. Sometimes the strongyles lodge in large numbers in the windpipe, forming themselves into a ball, and thus choke the animal to death.

_Symptoms._--It is liable to attack a number of animals at once, and the weakest are the first to give way. The animal has a remarkably forcible cough, distressing, and of a special hacking and paroxysmal character. A stringy mucus is sometimes expelled during the spells of coughing. This mucus contains the _Strongylus micrurus_, which can be detected, or their ova observed, under a low power of the microscope. The attack has a subacute character and is very exhausting. The parasites, by becoming entwined in b.a.l.l.s, seriously impede respiration, which is always remarkably labored in this disease.

_Treatment._--The affected calves should be placed in a dry stable, protected from dampness, and subjected to fumigations of sulphurous anhydrid or chlorin gas. The liberation of chlorin gas is brought about by the action of sulphuric acid, either on a mixture of chlorid of sodium and black oxid of manganese or on bleaching powder. Sulphurous anhydrid may be procured by burning sulphur. Some pract.i.tioners prescribe small doses of spirits of turpentine in linseed oil. The system requires good support, and the diet should therefore be liberal and nutritious. Equal parts of sulphate of iron, gentian, and ginger make an excellent tonic.

_Prevention._--Avoid pastures notorious for generating verminous bronchitis.

PLEURODYNIA.

Pleurodynia is a term applied to rheumatism of the intercostal muscles, the apparent symptoms being very similar to those of pleurisy. The animal is stiff, is not inclined to turn around, and the ribs are kept in a fixed state as much as possible. Pleurodynia may be distinguished from pleurisy by the coexistence of rheumatism in other parts and by the comparative absence of fever, cough, the friction sound, and the effusion into the chest. The treatment for this affection is the same as that for rheumatism affecting other parts.

DISEASES OF THE NERVOUS SYSTEM.

By W. H. HARBAUGH, V. S.

[Revised by John E. Mohler, V. M. D.]

THE NERVOUS SYSTEM.

The nervous system is the distinguis.h.i.+ng feature of animal life. Without it there can be no intelligence, no instinct, no sensibility, no perception; in fact, existence would be nothing more than vegetable life.

The senses--touch, taste, sight, hearing, smell--all depend on the nervous system. Motion depends on it. A muscle can not contract without receiving the stimulus from the nervous system. For example, if a nerve pa.s.sing from a nerve center to a muscle is severed, the particular muscle that is supplied by the cut nerve is paralyzed.

The nervous system is often studied in two divisions--the cerebrospinal division and the sympathetic division.

The cerebrospinal division consists of the brain and spinal cord, nerves, and ganglia. The nerves of this division convey the impulses of motion and sensation and supply all parts which are under the control of the will. For example, the voluntary muscular tissue includes all the muscles which act as the will directs. Another example: If anything comes in contact with any part of the skin, the impression is immediately perceived. All the special senses belong to this division.

The sympathetic division consists of nerves and ganglia. The muscular tissue, which acts independently of the will--as, for example, the stomach, intestines, womb, blood vessels, ducts, etc.--is called involuntary muscular tissue, and receives nervous stimulus from the sympathetic division.

The brain, spinal cord, and the ganglia are the central organs of the nervous system. The nerves conduct the nervous influence. The nerves terminate differently according to their function. The terminations are called end organs. The terminal end organs in the skin and other parts endowed with sensation receive the impressions, which are conveyed to the brain, where they are appreciated. They are so sensitive that the most gentle zephyr is perceived. They are so abundant that the point of the finest needle can not pierce the skin without coming in contact with them, and the sensation of pain is instantly conveyed to the brain. The terminal end organs of the nerves that supply the muscles are different, as they give the impulse which is conveyed by the motor nerves to the elements which const.i.tute the muscle, and this impulse is the excitation which causes the muscle to contract. The terminal end organs of the special senses of taste, smell, etc., receive their special impressions, and their respective nerves carry the impressions to the brain.

There are two divisions of nerves, the afferent and efferent.

The afferent nerves are those which convey the impression to the nerve centers. All the sensory nerves belong to this division.

The efferent nerves are those which convey the nervous impulse outward from the nerve centers, and they are further cla.s.sified according to the function of their respective centers. For example: Motor fibers carry the impulse from the nerve center to a muscle to cause contraction. Vasomotor fibers carry the impulse to the muscular tissue in the blood vessels, which regulates their caliber. The secretory fibers convey the impulse to the cells of the glands and excite the activity of the gland, and its particular product is secreted or evolved, as, for instance, milk in the mammary gland. Inhibitory fibers control or inhibit the action of the organ to which they are distributed, as, for instance, the heart.

Nerve centers may be considered as a collection or group of nerve cells.

Both the cerebrospinal and the sympathetic divisions have nerve centers.

The centers derive their special names from their functions. The brain is the great center of the nervous system, as it is the center of intelligence and perception. The centers of all the special senses, as well as the centers of various functions, are located in different parts of the brain.

Nerve centers also exist in the spinal cord and in connection with the sympathetic system.

A nerve is a cord consisting of a certain number of fibers of nerve tissue, inclosed in a sheath of connective tissue. Nerves divide and subdivide, sending off branches, which ramify in all parts of the body, and, as they near their terminations, they contain but one or two fibers.

The brain and spinal cord are contained within a bony ca.n.a.l, which forms a protective covering for them.

The spinal cord, or spinal marrow, lodged within the spinal ca.n.a.l, or hollow of the backbone, is continuous with the brain anteriorly, and terminates in a point in the sacrum (that part of the spinal column which immediately precedes the tail). The spinal cord gives off branches at each of the s.p.a.ces between the segments of the backbone. These branches form nerve trunks which carry both sensory and motor impressions and impulses.

The spinal cord is a grand nerve trunk to carry messages to or from the brain and to and from the reflex centers contained within itself.

The brain is contained within the cavity of the skull and is continuous with the spinal cord; there is nothing to mark the place where one leaves off and the other begins. The brain is the seat of reason and intelligence.

Voluntary effort originates from the brain. Coordination, or harmony of movement, is controlled by the rear portion of the brain, known as the cerebellum.

The meninges are the membranes, three in number, which envelop the brain and spinal cord, and separate them from the bones which form the walls of the cranial cavity and spinal ca.n.a.l.

The sympathetic, also called the ganglionic, division of the nervous system consists of two chains of ganglia, reaching from the head to the tail, situated beneath the spinal column, one on either side. The presence of the ganglia or enlargements on the cords give them their chainlike appearance.

The sympathetic nerves are closely connected with the cerebrospinal nerves, but are not under the control of the will.

INFLAMMATION OF THE BRAIN AND ITS MEMBRANES (STAGGERS).

Inflammation of the brain is technically termed encephalitis and of its membranes cerebral-meningitis, but as both conditions usually occur together, and since it is practically impossible to distinguish one from the other by the symptoms shown by the diseased animal, they may as well be considered together here as varieties of the same disease. Staggers, coma, frenzy, etc., are terms that are sometimes applied to this disease in its different forms or stages.

_Causes._--Severe blows on the head with a hard object, or the head coming violently in contact with the ground or other hard substance in a fall, may be followed by encephalitis. Irritation caused by tumors in the brain may produce inflammation. Feed containing deleterious matters--for example, ergot (see Pl. V) and other fungi which contain a narcotic principle--is the most frequent cause of this affection, and hence it is often called "gra.s.s staggers" and "stomach staggers." Highly nitrogenous feeds are blamed for causing this disease. Parasites, mineral and narcotic poisons, hot weather, and severe exertion or excessive excitement may cause this condition. Inflammation of the brain may occur as a complication of some infectious disease or may follow some forms of indigestion. In many localities certain plants have the reputation of causing staggers.

_Symptoms._--The symptoms vary much, but a careful observer will detect a trouble connected with the nervous system without much uncertainty. The first signs may be those of frenzy, but generally at the start the animal is dull and sleepy, with little or no inclination to move about; the head may be pressed against the wall or fence and the legs kept moving, as if the animal were endeavoring to walk through the obstruction; the body, especially the hind part, may be leaned against the side of the stall or stable, as if for support. The bowels are constipated; the urine, when pa.s.sed, is small in quant.i.ty and darker in color than natural. There may be trembling and even spasms of muscles in different parts. In the dull stage the animal may breathe less frequently than is natural, and each breath may be accompanied with a snoring-like sound. The pulse may be large and less frequent than normal. If suddenly aroused from the drowsy state, the animal appears startled and stares wildly. When moving about it may stagger, the hind quarters swaying from side to side.

If delirium ensues, the cow is commonly said to be mad. She may bellow, stamp her feet, run about wildly, grate the teeth, froth at the mouth. If she is confined in the stable, she rears and plunges; the convulsions are so violent in many instances that it is really dangerous for one to attempt to render aid. The body may be covered with perspiration. She may fall; the muscles twitch and jerk; often the head is raised and then dashed against the ground until blood issues from the nose and mouth; the eyes may be bloodshot and sightless; the limbs stiff and outstretched, or they may be kicked about recklessly; the head may be drawn back and the tail drawn up; the urine may be squirted out in spurts; often the "washer" (membrane nict.i.tans) is forced over the eye. When the convulsions cease they may be followed by a period of quiet unconsciousness (coma) which is more or less prolonged, when the animal may gradually regain consciousness, get up on its feet, and perhaps quietly partake of food, if there be any within reach, while at other times it arises with much difficulty and staggers blindly about the stall or field.

It must be remembered that all the foregoing symptoms are not always seen in the same case. In those cases usually designated "sleepy staggers" the general symptoms of drowsiness are presented, while in other cases the symptoms of frenzy cause the affection to be called "mad staggers." In other cases there are symptoms of paralysis, swaying of the hind quarters, inability to rise, etc., and sometimes these symptoms of paralysis are the most striking manifestations and continue until death. Acute cases are accompanied by fever.