Chapter III: Part 3

But chemiotaxis may be exerted from within the bloodvessel as well as from without. Bouchard, Massart and Bordet have shown that a tube containing a culture of bacillus pyocyanus, introduced beneath the skin of a rabbit attracts in a few hours a great number of leucocytes. But if, immediately after its introduction, ten cubic centimetres of a sterilized culture of the same bacillus are injected into a vein, very few leucocytes enter the tube inserted under the skin. The chemiotaxis seems to operate in this case from within the blood, and the desires of the leucocytes are satisfied without leaving the vessel. It would seem that in such cases the migration and protective work of the leucocytes is best exerted at the outset of the illness and before the toxic products have been poured into the blood in any quantity, whereas in the advanced stages when the blood is charged with ptomaines and toxins migration and phagocytosis would be likely to be limited and ineffective. The same consideration would forbid the use of drugs that check migration in all cases of attacks by microbes for which leucocytes have a positive chemiotaxis.

=Phagocytosis= is the act by which the leucocytes englobe and dissolve the invading microbe. By its amœboid movement the leucocyte flows around, and envelopes the microbe for which it has a positive chemiotaxis, and then begins the struggle of vitality between the two living germs. If the poison (leucomaine antitoxin,) and digestive ferment (enzyme) of the leucocytes are more deadly to the invading germ, than its ptomaines, toxins and enzymes are to the leucocyte, the white cell comes off the victor, and recovery takes place, but if the converse obtains the triumph is on the side of the microbe. As a rule much depends on the more or less deadly nature of the products of the invading microbe, on the numbers of the germ, the rapidity of its proliferation, and the consequent amount of its toxic products thrown into the system, on the one hand: And on the other the potency of the chemiotaxis of the leucocyte for the invading germ, the number of white cells that emigrate into the inflamed tissue and engage in the work of phagocytosis, and on whether the particular animal system and its white cells have sustained a previous attack by the same germ and has thereby been educated to produce a greater amount of the defensive proteids (leucomaine, antitoxin, enzyme) than it naturally would (acquired immunity).

Even with an abundant emigration of the leucocytes into the inflamed or invaded tissue, a number, greater or less, are usually destroyed by the bacterial poisons and pass into degeneration or liquefaction, as in the formation of pus, and yet the attacking germ may be overcome, destroyed and devoured by the rapidly increasing survivors. In general terms the migration of the cells is in inverse ratio to the susceptibility of the animal to the microbe or the disease which it causes.

The positive and negative chemiotaxis, which determine phagocytosis or prevent it, may be seen in the action of the leucocytes toward the germs of two diseases, to one of which the animal is susceptible and to the other of which it is not. Thus the leucocytes of the pigeon take in the bacillus anthracis and suffer nothing apparently, whereas the same white cells of the dove are repelled by the bacteria of fowl cholera which are not therefore found in their interior.

The leucocytes that migrate from the bloodvessels are in the main, the most numerous, (the neutrophile or polynuclear) form; the mononuclear leucocytes with horseshoe shaped nucleus also migrate but in much fewer numbers and are as a rule less occupied in phagocytosis. At the same time, these two forms may show each a preference for a particular microbe, the polynuclear cell sometimes devouring one which the mononuclear cell rejects, and the mononuclear cell taking in one which the polynuclear refuses.

The small round white cells (lymphocytes) and the eosinophile leucocytes take no prominent part in phagocytosis.

EXUDATION.

In inflamed vascular tissues one of the most important results is the exudation. This is not, however, a mere transudation of the liquid parts of the blood, as takes place in dropsy, but it is to a large extent a selective process determined apparently by the condition of the capillary walls, and the nature of the inflammation is stated according to the character of the exudate. The dropsical effusion contains little albumen, fibrine or cell forms, and does not coagulate. The inflammation exudate contains abundance of fibrine, cells and other solids and coagulates spontaneously in contact with inflamed tissue, or when removed from the body, by reason of the transforming leucocytes. Inflammatory exudate usually contains 6 to 8 per cent. of solids whereas the normal canine lymph contains 4 to 6. The exudate varies not only in different inflammations, but in successive stages of the same inflammation. The exudate may be mucous, serous, fibrinous or hæmorrhagic.

=Mucous Exudate.= In inflammation on a mucous or synovial surface the inflammatory exudation, mingled with the more or less altered secretion of the mucous glands, and the epithelial cells and leucocytes forms a viscid fluid, rich in mucin, and characterizing the _mucous_ or _catarrhal inflammation_. The nature of the discharge varies greatly, the serous character predominating at the start of the inflammation, and a thick, opaque creamy or semi-solid muco-purulent material appearing as the disease advances. It contains filaments of precipitated mucin insoluble in acetic acid or alcohol and cells in all stages of change from the exudation leucocyte and mucous cell to the pus corpuscle, the latter being characterized by its bipartite or tripartite nucleus rendered visible by contact with weak acetic acid.

=Serous Exudate.= This consists of the liquid elements of the blood with only a limited amount of fibrine formers and consequently little tendency to clot firmly. The presence of fibrinogen however serves to distinguish it from the liquid of mechanical dropsy, as does also the greater quantity of cells and nuclei of common salt and phosphates. It is usually straw colored in mass, but is sometimes slightly opalescent by reason of the numbers of cells and floating filaments of fibrine. Serous exudations take place in the early stages of inflammations (as in catarrh) and in inflammations of serous membranes (pleura, peritoneum, joints), in strong, vigorous subjects. They constitute the liquid contents of blisters whether raised by medicinal irritants, chafing, or heat. They clot under heat and nitric acid with a firmness proportionate to the amount of albumen.

These effusions are dangerous by reason of their interference with the functions of organs by pressure as with the dilatation of the lungs, the movements of the heart, the action of joints, or the integrity of the brain or spinal cord. When the causative disease has subsided they are usually speedily reabsorbed, the cells passing into the lymph vessels, or becoming degenerated, liquefied, and absorbed. Yet serous effusions often remain as permanent accumulations. For the blood staining of serous effusions and their clearing up, see under pleurisy.

=Fibrinous Exudate.= This is characterized by the amount of fibrinogen and fibro-plastin in its composition and by the comparative absence of leucocytes. It oozes through the vessels and coagulates in the tissues or on the surface of inflamed serous or mucous membranes. The more liquid part separating from the coagulum escapes from the free surface or accumulates in the lower part of the serous cavity. The coagulation is doubtless caused by the fibrine ferment derived from the rapidly proliferating cells and degenerating leucocytes. It usually occurs promptly in or on an inflamed tissue, but in contact with healthy structures only (as in a serous sac) it may remain fluid for an indefinite length of time. This exudate constitutes the false membranes that form on the pleura, pericardium or arachnoid, the coagulum of fibrinous pneumonia, and the plastic lymph on the surface of a granulating wound. It is especially injurious by reason of its enveloping organs (lungs, heart, bowels, iris) and subjecting to permanent compression by reason of its contracting, also by binding them to adjacent structures by false membranes. In coagulating it becomes first fibrillar then granular and finally undergoes molecular degeneration (Cornil and Remvier), or development into new tissue (Paget). When organized it usually takes the form of the adjacent tissue from which its trophic cells are derived. Thus in divided tendons, in serous membranes and in granulating wounds it is fibrous, and between the ends of a broken bone it is osseous. If however, the adjoining tissue is a highly organized one, like nerve or muscle it may be replaced by a simpler (fibrous, osseous).

Fibrinous inflammations are especially found in connection with inflamed fibrous tissues and in strong vigorous subjects.

=Blood Exudations.= In all inflammations there is some migration of blood globules (red as well as white) but seldom in quantity sufficient to stain the tissues materially. Minute ruptures of the capillary vessels are not uncommon, with punctiform clots in the tissues, but extensive escape of blood is mainly seen in penetrating or contused wounds of the loose, subcutaneous connective tissue, and in infective inflammations (anthrax, Rinderpest, swine plague, petechial fever, malignant catarrh, snakebites) with destruction of blood globules or extreme changes in the walls of the capillaries. Newly formed vessels in friable neoplasm are subject to blood effusions. In acute inflammations of serous membranes the exudate is usually of a dark port wine hue at first. In such cases it may pass in succession through all the stages of dark red, brick red, yellow, reddish, and chocolate color, before becoming milky and finally transparent.

=Croupous Exudate.= Croupous inflammation usually occurs on or near a mucous surface and is characterized by an exudation consisting mainly of fibrinous material entangling white cells, epithelium, a few pus corpuscles and some form of bacteria. In true diphtheria of children this is the Löffler bacillus, in the pseudodiphtheria, attending on scarlatina, etc., it is streptococcus pyogenus, in the diphtheria of calves it is bacillus diphtheriæ vitulorum, and in that of chickens and pigeons it is the bacillus diphtheriæ columbarum (Löffler). Pseudo-membranous inflammations therefore constitute a group agreeing in the nature of the exudate but differing essentially in the cause. This difference in the cause has a most material effect on the course and gravity of the disease. One form like true diphtheria in man not only extends into the tissues, and tends to necrotic changes, but also poisons the nerve centres by the toxic materials absorbed inducing troublesome paralysis, while another like croup of children establishes a violent but essentially superficial disease and when that recovers it leaves no ulterior ill effects elsewhere.

A =Chyliform exudate= has been noted in peritonitis in the dog the milky whiteness being due to fatty granules.

RESULTS AND PRODUCTS OF INFLAMMATION.

As nearly all inflammations have significant exudations it is well to follow these in their subsequent progress through reabsorption and removal, development into new tissues, necrosis, suppuration and ulceration.

=Resolution.= If an inflammation, slight in character and with only a moderate exudation, subsides and is followed by a rapid liquefaction of the cells and fibrinous coagula and a reabsorption of the exudate, so as to leave the part in its primary healthy condition structurally and functionally, it is said to have terminated by “_resolution_.” If this occurs with extraordinary rapidity it is said to have ended by “_delitescence_.” This is not always an unalloyed good, as often in delitescence, coagula and infecting material may be carried on by the circulation, to block the next set of capillaries in its course and set up new centres of inflammation. This is one form of “_metastasis_” though a more definite _metastasis_ is in rheumatism where the disease attacks one joint today and a distant one to-morrow.

=Inflammatory New Formations.= Of the growths in lymph there are two principal kinds: first, _the plastic_, _fibrinous_, _granular_ or _molecular_; and second, _the aplastic_ or _corpuscular_. The first form tends to develop into new structure, the second to disintegrate and decay. The tendency to one or other form depends largely on the strength or weakness of the system’s health, on the deficiency or excess of corpuscles in the exuded fluid, and on the distance of the latter from living tissues and blood supply. Much also depends on the predisposition of the genus, the tendency to suppuration in lymph being in a descending series from horse, ass, and mule, through ox and sheep, to dog, pig, and finally, the bird, in which latter suppuration is quite exceptional.

=Suppuration.= In inflammations of a high type, in those occurring on the skin or mucous membranes in which there is an extraordinary increase of nuclei and embryonal cells, and in lymph thrown out in excess at one point, so that its central parts are far from vascular tissue and nourishment, the cell elements undergo a rapid increase and degradation into pus-corpuscles, and its solidified intercellular lymph undergoes granular decay and liquefaction into pus.

While the above conditions are favorable to the formation of pus, the process of suppuration must now be recognized as an infective process due to the propogation of bacteria (mainly chain forms—_Streptococcus pyogenes_—cluster groups—_Staphylococcus py__ogenes_—and rod forms—_Bacillus pyogenes_). These or other bacteria are found in the pus of acute abscesses, and when absent in chronic abscesses are to be considered as having perished since the abscess was recent and active. Inoculation of a rabbit with an excess of the pus of an acute abscess produces general purulent infection (pyæmia) and early death; from a medium dose an abscess is produced; while from a small dose there is no effect whatever. In the latter case the bacteria are overcome and devoured by the abundance of vitally potent white blood globules and tissue cells. This pus-forming action of these bacteria explains the great difference in results in wounds exposed to the air and those in the interior of the body and far removed from air and its floating bacteria. A broken bone, with no wound in the skin and little injury to parts around the fracture, is readily repaired without any formation of pus, if merely kept still and immovable; whereas a broken bone, continuous with a wound through the skin, always tends to form pus or become otherwise infected, and is extremely dangerous even to life. The tendency of every open sore is to form pus on its surface but this may be arrested and avoided by preventing the access of germs, or by a free use of disinfectants and a covering which shall arrest and filter out the germs. Similarly in an abscess, evacuation followed by the injection of disinfectants, without the formation of any perceptible permanent opening to the outer air, will put a stop to the pus-formation. The subjection of an inflamed part to the control of these pus-forming bacteria is dependent on the lowered vitality and power of resistance of the inflamed tissues, and of the white cells of their circulating blood. Healthy parts can successfully resist them, though they are constantly present in surrounding air and on objects, but in this as in all other cases, of bacterial infection, so soon as the tissue is injured, inflamed and lowered in its power of vital resistance, the pyogenic bacteria assail it successfully. Hence, too, the more abundant exudations of lymph, the centres of which are farthest removed from the healthy tissues and from nourishment, are the most prone to suppuration. That the germs can make their way to such deep-seated exudations in the substance of solid tissues is to be accounted for by their gradual advance through the inflamed and weakened structures from the adjacent skin or mucous membrane, or in some instances by reason of their presence in small numbers in the blood. It is further noteworthy that those animals in which suppuration does not occur readily are such as have a special power of resistance to some other organic poisons. Thus the hog, which is supposed to be proof against snake-bite, is also, to a large extent, proof against the pus-forming bacteria.

=Pus.= This is a white, or yellowish white, creamy-looking product, composed of a clear, transparent fluid, rendered opaque by numerous floating pus-corpuscles. These pus-corpuscles have the same size as the white globules of the blood (¹⁄₂₅₀₀ to ¹⁄₃₀₀₀ inch) and are peculiar in that each shows within it three or more nuclei, which become visible on the addition of a drop of water or acetic acid. Each of the common embryonal cells found in the inflamed tissue usually contains two nuclei, the indication of the active increase by division into two, but when the supply of nutriment is checked the nuclei continue to divide, while the cells remain unchanged, and thus every cell comes to contain several nuclei in addition to fatty granules, and constitute pus-corpuscles.

When pus is formed in a well-maintained system and tissue, the outer layer of the lymph is developed into a fibrous sac enclosing the liquid pus and constituting an _abscess_. In an unhealthy system, or when the inflammation depends on some injurious poison, like that of erysipelas, this sac may not be formed, and the pus, burrowing into and between different organs, destroys the connections and substance—_diffuse suppuration_. When an abscess has formed in soft tissues its investing sac shrinks as it assumes the fibrous character, and the confined pus being incapable of compression, presses the membrane outward on the side in which the surrounding tissues are most loose and least resistant, hence, usually, though not always, in the direction of the skin; the soft tissues become absorbed and removed in the track of the advancing pus; and, finally, the latter reaches a free surface and escapes. Thus, an abscess usually bursts through the skin, but also, at times, through a mucous membrane into the lungs, bowels, etc., or through a serous membrane into chest, abdomen, etc. When an abscess is formed in bone or dense fibrous tissues which press equally on all sides, it may remain imprisoned for months and years after all inflammation has subsided, constituting an _indolent_ or _cold abscess_. When the imprisoned pus is inclosed by thick fibrous or resistant tissues at all points but one, it will make its way along the narrow passage of yielding tissue, but as the resulting outlet is constricted, long, and tortuous, the contents cannot readily escape through it nor the walls of the abscess contract so as to expel the confined pus, and the latter goes on forming and discharging through the narrow outlet for months or years. This is a _fistula_ or _sinus_.

=Healing by Adhesion or First Intention=. When a clean-cut wound has the blood staunched and its lips brought together without exposure to the air (or contact with pyogenic germs), they adhere at once and heal without pus or almost any appreciable formation of new tissue. Here the lymph thrown out on the cut surfaces agglutinates them, and the cells, multiplying, form a thin layer of embryonic tissue which gradually develops into a fibrous structure and repairs the breach without any perceptible scar.

=Healing by Second Intention. Granulation.= When a wound has caused destruction of tissue, or when a simple incision is left exposed to the air, the breach is filled up by new tissue through the process known as granulation. The superficial layer of lymph thrown out on the raw surface becomes oxidized and degenerates into pus, while the deeper layers become solid, fibrillated, the seat of cell growth, and are finally transformed into a fibrous structure. New bloodvessels form in loops in the developing lymph and constitute the bright red granulation-points which cover the raw surface. The fibrous tissue into which the lymph is transformed undergoes gradual contraction in development, and thus, day by day, the edges of the adjacent healthy skin are drawn in, so as to cover the wound more or less perfectly, and a slight scar only is left when healing has been accomplished.

=Granule Corpuscles and Masses.= This is another degenerative transformation in lymph and, is seen mainly in inflamed glands and brain and lung tissue. The cells found in the exuded lymph are made up of granules ¹⁄₁₀₀₀₀ inch in diameter, and besides these, large, irregularly shaped masses of granules are extended along the capillary bloodvessels. After the lymph has coagulated these granular masses soften and liquefy preliminary to reabsorption and removal, and the restoration of the tissue to a healthy condition. When in excess this softens and disintegrates the tissues, leading to permanent loss of substance. See _granular_ degeneration.

=Interstitial Development of Lymph into Tissue.= This is equivalent to what takes place in the formation of the sac of the abscess or of granulation-tissue. The liquid lymph in coagulating, becomes fibrillar, and the cells and nuclei of the adjacent tissue, having an abundant supply of blood and nutriment, multiply first as simple, rounded embryonic cells, then deposit around them new tissue, becoming elongated, spindle-shaped, branching, etc., and thus get imbedded in a fibrous material of their own formation. These new formations are usually of a low type of organization, like white fibrous tissue or bone, and hence, although breaches in the higher structures like muscle, nerve, gland, skill, are filled up, it is usually only by the drawing together of the remaining healthy parts by these new formations without the restoration of any of the original tissue which has been destroyed. The cicatrix (scar), alone is made up of new material.

Lymph developing in this way may undergo any degeneration to which normal tissues are subject. Thus it may undergo black pigmentary (_melanotic_) degeneration, it may become impregnated with lime-salts (_calcified_), it may wither up into a hard _gelatiniform_ or _horny_ mass, or it may undergo _fatty_ degeneration.

=Fatty degeneration= is the most common form, and consists in the excessive deposit of fatty granules, first in the cells which are in excess or badly nourished, and next in the adjacent tissue, the normal elements of which are replaced by fatty granules.

=Softening= is an almost constant result of inflammation. The exudate infiltrates and separates the tissue elements, destroying their cohesion; the liquefaction of these elements impairs this still further, and the more or less perfect transformation of the tissue into embryonic tissue entails the loss of its rigidity and power of resistance. Thus the inflamed brain-tissue may become a mere pulp, and the inflamed bone may be cut with a knife.

=Ulceration= is closely allied to softening. On the surface of a sore there is an excessive exudation of lymph, which loosens and disintegrates the layer of lymph that is already in process of development, and also a part of the tissue beneath. The cells in these parts fail to develop naturally and to build up good tissue; they become fatty, die, and together with the tissue in which they lie, break down and pass off as a pulpy debris. Thus the sore constantly deepens and widens, or at least refuses to contract and heal. It is usually the result of bacterial infection.

=Gangrene= or =death of a part= is another effect of inflammation. It results usually from the cutting off of the blood supply through the obstruction of the bloodvessels; by the pressure of excessive exudation in unyielding structures, as in bone, or under the hoof; by implication of the inner coats of the bloodvessels in the inflammation, when the contained blood will clot and obstruct them; or by blocking with the blood clots that have been formed at a distance and washed on in the blood current to be arrested when they reach vessels too small to admit them. Like suppuration, gangrene is associated with and often caused by a bacterial growth. The dead mass remains as an irritant, and is slowly separated by the formation around it of embryonal tissue, granulations and pus. A second form is _molecular gangrene_, in which the cells and minute elements of the tissue die, and are cast off, leading to phagedenic (eating, extending) sores, as noted above under Ulceration. When gangrene occurs on an exposed surface, that may be altered from the normal color into shades of yellow, brown, green, red, or black, according to the amount of blood and the stage of decomposition, and may be cut without pain, if the subjacent parts are not pressed upon; it may be soft, may pit on pressure, may crackle under the hand from the evolved gases of decomposition, and may be covered with blisters (_phlyctenæ_) with red, grumous liquid contents (_moist gangrene_); again, it may be white, as after freezing, or it may be dark colored, dry, and horny, as from ergotism (_dry gangrene_).

FEVER.

Definition. Symptomatic. Idiopathic. Symptoms. Contagion. Incubation.
Premonitory symptoms. Chill, rigor. Reaction, hot stage.
Defervescence. Crisis. Lysis. Natural temperature. Fever temperature.
Retention of water in the system. Production of waste materials.
Typhoid condition. High fever, low, hectic. Treatment in vigorous
subject, in weak one. Regimen. Solipedes. Ruminants. Carnivora. Drink.
Rest. Clothing. Air. General and local bleeding. Cupping. Warm baths,
tepid, compresses, derivatives. Cold. Diaphoretics. Laxatives.
Diuretics. Sedatives. Alkalies. Antipyretics. Stimulants. Tonic
refrigerants. Tonics. In low fever. No depletion. Judicious
elimination. Stimulants. Refrigerants. Antiseptics. Diet. Local
treatment of inflammation. Cold. Astringents. Antiseptics. Warm
applications. Stimulating embrocations. Blisters. Firing. Massage.
Suppuration.

_Definition. Whether occurring as an accompaniment of inflammation or
independently of it, fever is an unnatural elevation of the
temperature of the body, the direct result of an excess of destructive
chemical change in the blood and tissues, and more remotely of
disordered nervous function._

Of all extensive inflammations fever is the constant result and accompaniment, rising as the inflammation rises or extends, and subsiding as the inflammation subsides. It also occurs as a distinct affection, as in all the infectious diseases, as the result of a specific irritating poison in the system, and then is the manifestation of the disease, while a local inflammation may or may not be present as a special secondary feature of the malady or as an accidental complication.

_Symptoms of Fever._ Fever is marked by certain definite stages, each of which has its own special manifestations. In the cases due to a specific disease germ, or _contagium_, these are, however, preceded by a period of _latency_ or _incubation_ in which no symptoms whatever are manifest, but during this time the germ is rapidly multiplying in the system, and it is only when it has gained a certain increase that it disorders the nervous system, wastes the tissues, raises the temperature of the body, and induces the other phenomena of fever. The same may be said to hold in the fever attending on inflammation. The slight and circumscribed inflammation is at first productive of no fever, and it is only when it gains a certain extent that the nerves and nutrition are disordered so as to bring about a feverish condition.

_Premonitory Symptoms._ These usually last but a few hours and are often entirely absent or unnoticed. There is a lack of the customary vigor and spirit, an indisposition to exertion, a loss of clearness and vivacity of the eye, a manifest dullness, with hanging of the head, and frequent shifting of the limbs as if fatigued. Appetite is less sharp and ruminants chew the cud less heartily or persistently.

_Cold Stage._ These are soon succeeded by the _chill_, _rigor_, or _shivering fit_, in which the hair, especially that along the back, stands erect (staring coat), the skin is cold and adherent to the structures beneath (hidebound), the extremities (legs, tail, ears, horns, nose) are cold, and the frame is agitated with slight tremors, or even a shivering so violent that a wooden floor or building is made to rattle. The back is arched, the legs brought nearer together (crouching), the mouth is cool and clammy, the breathing hurried, the pulse weak, and it may be rapid, but with a hard beat, the bowels costive, and the urine higher colored than natural. The temperature of the interior of the body, taken by a thermometer in the rectum, is already found above the normal, the excessive destruction of tissue having begun, and the blood driven from the cooler surface, and accumulating in the hot interior, at once favors tissue change and maintains the extra heat thereby produced. In cattle the end of the tail is soft and flaccid from this stage onward. The _cold stage_ lasts a few minutes, or one or two days in different cases.

_Hot Stage._ The hot stage appears as a reaction from the chill, the contraction in the minute vessels of the skin giving place to dilatation, so that the whole surface, including the extremities, becomes hot and burning, but still dry and parched. The burning is especially noticeable in the more vascular parts, like the roots of the horns and ears, the muzzle or snout, the mouth, the hoofs, the bare parts of the paws in carnivora, and the mammæ (udder) in suckling animals. The mucous membranes lining the nose and mouth become hot and red, the breathing freer, but not less rapid, the pulse softer but accelerated, appetite (and rumination) greatly impaired or lost, thirst great, costiveness increased, urine diminished and of a higher color, the flow of milk greatly impaired or entirely arrested, and the dullness and prostration greatly increased.

The hot stage lasts longer than the cold one, usually persisting until death or convalescence. It may alternate with chills throughout the whole course of the illness, and in the fever of inflammation the interruption of the _hot stage_ by a chill usually implies either a considerable extension of the inflammation or the occurrence of suppuration.

_Defervescence._ The decline of the fever may take place by a sudden reduction of the body temperature to the natural standard, or near it, and a sudden and general improvement in the symptoms (crisis), or by a slow improvement from day to day through a more or less tedious convalescence (lysis).

_Fever Temperature._ A temporary rise of one or two degrees is unimportant, but a permanent rise indicates fever. A rise of ten or twelve degrees is usually fatal. A sudden fall to or below the natural, unless with general improvement in the symptoms indicates _sinking_. A similar fall, with a free secretion (perspiration, urination, relaxed bowels) and general improvement in symptoms, betokens recovery. For normal and febrile temperature see Semeiology.

_Retention of water in the fevered system_ is as significant as the elevated temperature. The patient drinks greedily but all the secretions are arrested or diminished, and liquids go on accumulating in the system. The sudden bursting forth of secretions (especially sweating) implies that the fever has, at least temporarily, given way.

_The production of waste matters in the system_ is necessarily proportionate to the amount of tissue destroyed. This appears in the blood mainly as urea, the organic acid of urine (hippuric in herbivora, uric in carnivora), together with phosphates, sulphates, and chlorides. These thrown off by the urine give it its high density. If not thus thrown off they remain as poisons in the circulation and bring about that prostrate, sunken, debilitated condition which characterizes the advanced stages of all severe and continued fevers—_the typhoid condition_. This is not to be confounded with the specific _typhoid fever_, in which a special fever germ expends itself, mainly on the bowels, and that runs through a regular course. The _typhoid condition_ is that state in which an animal system, already greatly weakened by a severe disease, and perhaps further prostrated by a specific disease-poison, is subjected to a species of poisoning by the retained chemical products of the waste of the tissues.

_Types of Fever._ These are as characteristic as the types of inflammation, and of the same kind. The _strong_ type of fever which attends on an acute inflammation in an otherwise healthy vigorous system, is spoken of as a _high_ or _inflammatory_ fever. The _weak_ type which occurs in a broken down or debilitated system, or in connection with the action of a specific disease germ, or with the saturation of the system by waste chemical products is known as _low_, _typhoid_ (better _typhous_), or _adynamic_ fever. That form which persists in the utterly debilitated system, where the power of assimilation is practically lost, is known as _hectic_.

TREATMENT OF INFLAMMATION AND FEVER.

Treatment will be guided very largely by the type of the attendant fever. If that is of a high type, with a hard, full, rapid pulse, bright red mucous membranes, a clear eye, and well sustained strength in a strong, vigorous animal, what is known as antiphlogistic (depleting, depressing) treatment is admissible at the outset. But in many cases with a low type of fever, a weak, rapid pulse, pallid, yellow, or livid mucous membranes, a coated tongue, a dull or sunken eye, much depression and prostration, swaying on the limbs in walking, pendant head, ears, eyelids and lips, and varying and irregular temperature of the limbs, etc., such measures are forbidden from the first, and tonics and stimulants are demanded from the outset. Between the two extremes there are many grades, which demand a judiciously adjusted intermediate treatment. The general principles only of each characteristic form of treatment can be here formulated, it being understood that no two cases can be most advantageously treated in precisely the same way, but that according to its special grade each case will demand its own specific management applied according to the skill of the physician.

_Regimen._ An antiphlogistic diet will consist in a moderate or very sparing amount of non-stimulating food of easy digestion (wheat bran or oil meal in warm, sloppy mash, carrots, turnips, beets, potatoes, apples, pumpkins; fresh, tender, green grass or in winter a little scalded hay, may be taken as examples). _Ruminants_ should have no food necessitating chewing of the cud; thus the roots, etc., should be pulped or boiled, and hay and even grass must be interdicted until rumination is re-established. When food is absolutely refused for days in succession well-boiled gruels of oatmeal, barley-meal, linseed meal, bran, etc., may be given from a bottle or by injection. _Dogs_ and _cats_ should have only vegetable mush (unbolted flour, barley, or oatmeal) with just enough beef-juice to tempt the animal to eat a little. Milk with an admixture of oxide of magnesia, or even lime water is often at once palatable and cooling. _Drink_ should be pure water, cool, if kept constantly fresh before the animal, but warmed to something less than tepid if supplied only at long intervals, so that the thirsty patient is not tempted to drink to excess and chill himself. _Rest_ in a clean, well-aired building, free from draughts of cold air and with a southern exposure, is desirable, especially in winter. The best temperature is usually sixty degrees to seventy degrees, especially in inflammations in the chest, and extremes of temperature are to be avoided. _Clothing_ will depend on the weather. In warm weather it may be often discarded, while in winter it should always be sufficient to obviate the access of _chill_ and consequent aggravation of the disease. Whenever the atmosphere can be kept warm only at the expense of impurity it is better to secure the comfort of the patient by the requisite clothing than to subject him to impure air. As the extremities are the first to suffer from cold, loose flannel bandages to the limbs are often imperative.

_Remedies._ _General bleeding_, a great resort of our fore-fathers, has been long all but discarded from modern practice. Today it is rarely resorted to, except to save from an urgent and extreme danger, as in the plethoric cow merging into parturient apoplexy, or the fat and overdriven horse, gasping for breath and life, in general acute congestion of the lungs. There are other cases of extensive acute and dangerous congestions, especially in a strong, vigorous, and plethoric patient, in which general bleeding in beneficial in warding off threatened death; but sound, discriminating judgment is necessary to its safe employment. When resorted to at all, the blood should be drawn from a large orifice, in a full stream, to secure the desired depressant effect with the smallest loss of blood, and the patient should be kept especially quiet and apart from all excitement which would tend to counteract the sedative action.

_Local bleeding_ is more extensively applicable than _general_, as it usually effects the same purpose without the permanently weakening effect. It acts in two ways, first, by emptying and contracting the vessels in the skin over the inflamed organ, it solicits a sympathetic contraction of the capillary vessels in that organ itself, and thus inaugurates a progress toward recovery; and second, by so much as it draws blood to the surface it diminishes the blood pressure on the deeper inflamed organ, and affords a better opportunity for the restoration of the healthy circulation and function. Local bleeding may be practiced by simple scarification or leeches, or better, by cupping with or without scarification. To apply leeches, the skin must first be shaved. To cup, it must at least be greased. As a cup, an ordinary large drinking-glass may be used, the air contained in it being driven out by a lighted taper, and then the taper being withdrawn, the mouth of the cup is instantly and accurately applied on the skin and held there, until, as it cools, it draws up the skin within it and clings like a sucker. A number of these may be applied according to the extent of the inflammation, and, if desired, they may be removed, the part scarified, and the cup reapplied. The cupping usually effects more than a mere local attraction of blood; it very commonly causes a free circulation in the whole skin, a generally diffused warmth, and even perspiration. Thus we may secure the derivation of blood from the inflamed part, the cooling of a large mass of blood in the extensive cutaneous circulation, the cooling of the entire system by the return of this blood internally, the elimination of injurious waste matters through the skin, the lowering of the febrile heat and tension, and a better functional activity of all the organs of the body.

Similar good results are obtained from all remedies that induce surface warmth and vascularity and a free secretion from the skin.

_Warm baths_, for animals to which they can be applied, abstract blood temporarily from the inflamed internal organs, diminish the blood pressure, and really cool the system, beside securing elimination from the skin and other secreting surfaces. They may be commenced warm (80° F.) and gradually cooled down to 65° F. after the skin has become freely active. In the larger quadrupeds, in which the warm bath is too often practically impossible, the same revulsion of blood and warmth to the skin may be secured by _rags wrung out of hot_ (_almost scalding_) _water_, wrapped tightly round the body, covered with two or more dry blankets, and kept tightly applied against the surface by elastic circingles. The legs may be rubbed with straw wisps till warm, and then loosely bandaged, or applications of red pepper, ammonia, or mustard, may be made prior to bandaging. In place of hot water rugs, bags loosely filled with bran, chaff, or other light agent, heated to 110° F., may be applied round the body, or, where it is available, a Turkish or steam bath may be resorted to. These hot cutaneous applications, to produce glow and perspiration, are especially valuable in the chill that heralds a violent inflammation, and if that can be suddenly checked by this means the inflammation will often be warded off, or at least rendered slight and easily controllable. After perspiring for half an hour the patient may be gradually uncovered, rubbed dry, and covered with a dry, warm blanket. If the skin is still glowing, a slight sponging with cool or cold water may beneficially precede the rubbing and drying.

_Cold Baths._ In cases of very high fever a full cold bath (68° F.) may be employed for fifteen minutes, and repeated as often as the temperature rises. In many cases of parturition fever in cows great benefit accrues from sponging the body with cold water and allowing it to evaporate from the burning skin. In the extreme fever of heat apoplexy (sunstroke), with a temperature of 110° F. and upward, a strong current of cold water from a hose directed on the head and body often gives the best results. In ordinary fevers in large animals the _cold pack_ will often serve a good purpose. Wring a blanket out of water (cold or tepid, according to the height of the fever and the strength and power of reaction of the patient), wrap it round the body, cover it with several dry blankets so that no part is exposed, and keep the whole in close contact with the skin by elastic circingles. In fifteen minutes the skin should be glowing and perspiring, and in half an hour the wrappings should be removed, a little at a time, the parts rubbed dry and covered with a dry woolen blanket. It may be repeated as often as the fever rises.

_Diaphoretics._ Besides these remedial methods of inducing a revulsion and glow in the skin with perspiration, _medicinal diaphoretics_ may be resorted to. Among these may be included _copious drinks and injections of warm water_, _acetate of ammonia_, _antimony_, _ipecacuan_, or _pilocarpin_, or one of the sedatives, _aconite_, _veratrum_, or _opium_, etc. Many a threatened acute inflammation has been to a great extent cut short and nipped in the bud—the stage of chill—by warm clothing, active hand rubbing, and such an apparently unscientific nauseant as tobacco.

When the preliminary stage has passed and the hot stage of the fever has set in, cooling and eliminating agents are especially called for.

_Laxatives._ In many cases, and especially in those with marked constipation or bowels loaded with indigestible materials, a laxative is beneficial. For the horse, aloes, or, often better, sulphate of soda, and for cattle or sheep, the latter, or Epsom salts, will at once remove an irritant, cool the general system, draw off much blood and nervous energy to the bowels, and secure a considerable depletion and elimination from the intestines. For swine, dogs, and cats castor oil or salts may be used, and for fowls castor oil. If the mucous membranes are yellow, the tongue furred, and feces scanty, hard, and fœtid, a dose of calomel (horse or ox, one drachm; sheep or pig, one scruple; dog, three grains; chicken, one-half grain) with tartar emetic (horse or ox, two drachms; sheep, twenty grains; swine, one-half grain; dog, one-fourth grain; chicken, one-eighth grain) may be given and followed in ten hours by one of the laxatives named above.

_Diuretics._ In the absence of any manifest disorder of the digestive organs, the laxative may be omitted and refrigerant diuretics resorted to. Acetate of ammonia or potassa, nitre, tartrate of potassa, carbonates of potassa or soda, may be used along with sedatives.

In cases of infectious disease with poisoning by ptomaines and toxins the elimination of these by the bowels and kidneys is of the greatest importance.

_Sedatives._ Of the sedatives, aconite, bromide of potassium, veratrum, hyoscyamus, or chloral hydrate may be used according to the special indications.

_Alkalies._ _Resolvents._ When the organ inflamed is a serous membrane in which dangerous adhesions or other functional disorders are likely to occur from newly formed false membranes, their formation should be counteracted as far as possible by the free use of alkalies (carbonates of soda, potash, or ammonia, nitre, iodide of potassium, muriate of ammonia, etc.), and in the same conditions excessive effusion should be controlled by free action on the kidneys.

_Antipyretics._ To reduce the febrile temperature and especially, when caused by the ptomaines and toxins of bacterial infection, agents like acetanilid, antipyrin, exalgin, analgene, benzanilide, salicylate of soda, and quinine have been largely employed and will usually lower the temperature several degrees in a few hours. They nearly all depress the vital forces, or hinder reparatory processes, so that their use is to be carefully guarded. Quinine which is less depressing than the others hinders migration of the leucocytes and thus stands in the way of successful phagocytosis. With a dangerously high temperature they may be temporarily admissible, but they should be suspended as soon as possible. In all ordinary cases they are probably better avoided. A judicious use of the cold or tepid bath, or of wet compresses is incomparably safer and more generally applicable.

_Stimulants._ When the disease results in great prostration or when symptoms of septic or ptomaine poisoning set in stimulants are often required to sustain the flagging heart and circulation. These may be alcoholic, ammoniacal, etherial, camphor, digitalis, etc.

_Tonic Refrigerants._ Later, when both inflammation and fever have been somewhat reduced, temperature, breathing, and pulse rendered more moderate, eye clearer, and even appetite perhaps slightly improved, the sedatives may give place to refrigerating tonics, such as mineral acids (nitric, muriatic, sulphuric, or phosphoric), in combination with bitters (quassia, cascarilla, calumba, gentian, salicin), without as yet the suspension of refrigerant diuretics. Thus for the horse the following Recipe: Pharmaceutical nitric acid, two drams; infusion of gentian, ten ounces; nitrate of potassa, two ounces. Dissolve. Give one ounce every six hours.

_In Convalescence._ When convalescence has fairly set in, the fever has subsided, and there remains merely some debility with a remnant of the inflammatory exudation to be removed or organized into tissue, or when an abscess has developed and burst, the tonics must be even more freely given, the mineral acids may even give place to preparations of iron or cod-liver oil, and the diet must be made increasingly liberal. But throughout the whole progress of the disease the bowels should be carefully watched. Costiveness may quickly undo all that has been gained, hence any indication of this should be met by laxative food (boiled flaxseed, etc.), or, this failing, by injections or laxatives. Similarly, if a freer action of the kidneys seems to be necessary for elimination of waste matters or to reduce fever, diuretics should be continuously kept up.

TREATMENT OF ADYNAMIC INFLAMMATION AND FEVER. In treating _low asthenic_ or _adynamic inflammation_ all depression and depletion is to be carefully avoided. Even _laxatives_ must be employed with extreme caution. If absolutely necessary it is best to give them in small (half) doses and supplement their action by liberal injections of hot water. Elimination of waste matter from the blood and system is still to be sought, but it must be by _stimulating diuretics_ (sweet spirits of nitre, carbonate, acetate, or muriate of ammonia, digitalis), and direct _stimulants_ and _tonics_ must be given from the first (ammonia, wine, strong ale, whisky, brandy, ether, gentian, calumba, nux vomica). For the horse the following may serve as an example: Recipe: Sweet spirits of nitre, four ounces; sulphuric ether, two ounces; tincture of gentian, ten ounces; digitalis, one dram. Mix. Dose, two ounces in a pint of cool water four times a day. When there is great debility and prostration ammoniacal and alcoholic stimulants must be given freely, while if the fever heat rises very unduly the cooling diuretics (citrate, tartrate, or acetate of potassa, or nitre, etc.), and even sedatives (bromide of potassium, hydrobromic acid, chloral hydrate, salicin, salicylate of soda), must be resorted to. If there is any indication of a special depressing poison in the system, or of the absorption of septic or other noxious matter from a wound, antiseptics (hydrochloric acid, or salicylic acid, sulphite of soda, quinia, or chlorate of potassa) may be advantageously added to the prescription.

In these cases of asthenic inflammation, as in the advanced and debilitated stages of sthenic inflammation, the diet should be as good as the patient can digest. Boiled oats, barley, or flaxseed, rich, well-boiled gruels, and beef-tea (even for herbivora,) may frequently be resorted to with advantage.

_Local Treatment of Inflammation._ In all forms of superficial inflammation the local treatment occupies an important place. The persistent application of _cold_ (cold water in a stream, icebags, freezing mixtures) will sometimes overcome the tendency to inflammation or arrest it. This is especially sought when a violent inflammation (as in a wounded joint) threatens to destroy an important organ. If adopted, it must be persisted in, as if it is suspended too soon the reaction is likely to make matters worse than ever. _Cold astringent applications_ have a similar tendency. Sugar-of-lead, one-half ounce; laudanum, one ounce; water, one quart, may be kept applied by means of a linen bandage. The water may often be advantageously replaced by extract of witch-hazel. If the inflamed part is superficial the lotion may be made _antiseptic_ (carbolic acid, one dram; or sulphurous acid solution, five ounces; water, one quart). _Hot applications_, _fomentations_, _poultices_ are nearly always appropriate but they should be made antiseptic to prevent bacterial development. When adopted they should like _cold_ ones be kept up as continuously as possible. These soothe alike the superficial and deeper parts, the latter through sympathy, producing first a relaxation of vessels and tissues, and later a contraction of the former attended by pallor of the surface. They greatly favor suppuration when that is already inevitable, though in other cases they may obviate it by checking at an early stage the acute inflammatory process on which it depends. Any bland agent that will retain heat and moisture will make an excellent poultice, though flaxseed-meal is the type of a soothing demulcent application. Very slight inflammation may be successfully treated at the outset with a _stimulating embrocation_ (alcohol or camphorated spirit), yet in the more violent type of acute inflammation all local excitants tend to aggravate the disease. In these violent forms the activity of the disease should be first abated by local soothing and general sedative measures, and then the part over the inflamed organ may be safely treated with a stimulating liniment or even a blister. In such cases the liniment first acts as a derivative of blood and nervous energy from the inflamed part, and later and still more beneficially by securing in it a sympathetic healing process, like that set up in the skin. It is further probable that the absorbed albuminoids, which have been modified in the congested part often exercise a decided effect on the inflamed tissue. In raw sores where inflammation has been set up the granulations may become dropsical or excessive, bulging beyond the adjacent skin as _proud flesh_. This should be repressed by touching it gently with some mild caustic (lunar caustic), so as to produce a thin, white film, and the remote cause of the inflammation (often a local irritant) should be sought and removed. In some unhealthy sores tending to excessive granulation, the compound tincture of myrrh and aloes may be applied daily with great benefit. When the granulations become excessive they may be scraped down to the level of the skin and then treated with an antiseptic (iodoform, boric acid, acetanilid, aristol).

_Blistering._ In subacute and chronic inflammations and in those acute forms in which the violence of the inflammatory action has been already subdued by soothing measures, blisters and other counterirritants may be employed to counteract the remaining inflammatory action. These act primarily by drawing off blood and nervous energy from the inflamed organ to the skin, and secondarily, by establishing a sympathetic healing process in the diseased part, simultaneously with the work of recovery in the skin, when the blister has spent its action. But if applied above a part which is still violently inflamed, there is apt to be serious aggravation, through this same sympathy with the part suffering under the rising of the blister. In this way great and irreparable injury is often done through the laudations of particular blisters for the cure of given diseases, without any reference to the stage or grade of such disease. The value of a blister depends far more on the time of its application than on the ingredients of which it may be composed.

_Firing._ This acts in nearly the same manner as a blister, and demands similar caution in its application. It is especially available in subacute and chronic diseases of the joints, bones, and tendons, and may be made more or less severe according to the nature and obstinacy of the disease. It is applied in points or in lines at intervals of one-half to one inch, and penetrating one-third, one-half, or entirely through the skin. The hotter the iron the less the pain, but the greater the danger of destruction of the intervening skin by the excess of radiating heat. Hence the contact of the heated iron with any one part must be judiciously graduated to the heat of the iron and the delicacy of the skin, and should not exceed the fraction of a second.

_Massage, Rubbing._ In chronic inflammation and even in some acute forms, with considerable exudation, rubbing or massage is of great value. It hastens the progress of the blood through the veins, tends to restore the normal circulation in the stagnant or partially obstructed capillaries, moves on the exuded liquids in the lymphatic plexus, rendering the absorption more active, and at once prevents the process of disintegration of the tissues and obviates, the necessity for their solution and removal. This may be largely accomplished by the use of the brush or rubber, or by careful manipulation especially in the direction of the veins. If the inflammation is near the surface the use of antiseptic and deobstruent agents will heighten the good effect. Iodoform, iodide of potassium, boric acid may serve as examples.

_Suppuration._ _Abscess._ The great variety of the causes and forms of suppuration would forbid any extended notice of its treatment in this place. It seems preferable to refer the reader to the subject of pyæmid and the various surgical and medical diseases in which suppuration takes place.