CHAPTER III.. Diseases of the Kidneys.

DISEASES OF THE KIDNEYS.

CONGESTION OF THE KIDNEYS.

Congestion of the kidneys is not a morbid condition in the strict sense of the term, for it is merely the forerunner of nephritis caused by infectious diseases or intoxications (primary active congestions) or the final consequence of other diseases, such as diseases of the heart or liver, mechanical compression of the vena cava or renal veins (secondary passive congestion, cardiac kidney).

Nevertheless, under certain circumstances the development of nephritis may be arrested at the primary congestive stage, and it is only then that an opportunity occurs of studying it as a definite complaint.

=Causation.= All infections accompanied by lesions of the kidneys, and these are numerous (gangrenous coryza, anthrax, parasitic hæmoglobinuria), produce congestion of the kidneys.

Cold also acts directly under certain conditions, as do large doses of diuretics, irritant foods the principles of which are eliminated through the urine (fermenting or putrid sugar-pulp, for example), and foods rich in resins, essential oils, various glucosides, tannin, etc. (young shoots of trees during the spring-time).

=Symptoms.= The symptoms are difficult to define accurately, and the diagnosis can only be arrived at with the aid of the history.

Renal congestion produces pain, indicated by dull colic and repeated and ineffectual attempts to urinate, suggesting acute cystitis. The patients lose appetite, and present all the general symptoms of marked visceral inflammation, viz., fever, acceleration of breathing, somewhat tumultuous action of the heart, etc.

External or internal examination of the kidneys reveals abnormal sensitiveness. The urine is of a dark or bright-red tint, owing to the presence of red blood corpuscles. These blood corpuscles are precipitated on placing the fluid in a tall glass, and can be detected, together with renal epithelium, by microscopic examination.

=The diagnosis= is somewhat difficult, and it requires very careful attention to distinguish between congestion of the kidney and true nephritis.

=The prognosis= should always be reserved until it is certain that acute nephritis will not ultimately develop.

=The treatment= consists in removing the cause of the congestion; rich foods, or foods containing irritant principles, should, therefore, be avoided, as also the administration of diuretics, etc.

Otherwise, the treatment is similar to that employed in all visceral inflammations: bleeding to the extent of two to four quarts, according to the size of the animals, warm poultices to the loins and flanks, dry friction, mucilaginous drinks and emollient decoctions of barley or pellitory. The animals should be kept in a warm place.

In cases of passive and secondary congestion, treatment must be directed towards improving the condition of the organ primarily affected, whether it be the heart, liver, or lymphatic glands.

ACUTE NEPHRITIS.

The term nephritis applies to inflammation of the renal tissues. Clinically, two forms only can be distinguished, the acute and the chronic.

As regards its pathological anatomy, the inflammation may principally affect either the interstitial tissue or the epithelial parenchyma, a fact which has suggested the division of the condition into epithelial nephritis, interstitial nephritis, and mixed nephritis. Clinically, such distinctions are impossible; and in reality all forms of nephritis are to a varying degree mixed, the lesions predominating in one or other of the constituent tissues. These lesions depend on the extent, intensity, and duration of the inflammatory attack, whatever the primary causes. All the constituent tissues of the kidney may be affected, simultaneously or individually: the Malpighian corpuscles, the convoluted tubules, the collecting tubules, or the interstitial connective tissue.

=Causation.= Cold seems to be an important factor. All acute or chronic intoxications in which the toxic principles are eliminated by the kidneys, such as poisoning by cantharides, fermented beet pulp, young shoots of trees or toxic plants, may cause acute nephritis.

Infectious diseases, such as gangrenous coryza, hæmoglobinuria, tuberculosis and post-partum infections, also play an important part, whether the nephritis be direct, that is to say, the result of the infecting agent itself, or indirect, i.e., produced by toxins generated in the body. In female animals gestation is an often unsuspected cause. Moussu believes that albuminuria is frequent during gestation, and although in most cases it is only of moderate degree, he thinks it is often associated with subacute nephritis, which might be aggravated by an accidental cause.

Many forms of nephritis are overlooked in consequence of their slight character.

=Symptoms.= The early symptoms are similar to those of congestion of the kidney, viz., dull colic, excessive sensitiveness over the region of the loins, passage of pink urine, loss of appetite, and fever. At a later stage, in cases of acute nephritis due to cold, the animal stands with the limbs close together and remains stationary, arching the loins and back, which are held stiffly. The animal obstinately refuses to move in consequence of the pain produced by so doing.

The general condition becomes grave, respiration is rapid, the pulse frequent, the artery tense, the muzzle dry, the accessible mucous membranes are injected, and appetite is almost entirely lost.

Urine is frequently passed, but the act causes pain, and the quantity is small. Absolute anuria is rare, and does not last long.

The urine is generally sanguinolent, at least at first, but to a very varying extent. It is always albuminous, the quantity of albumen varying enormously, and on microscopic examination, is usually found to contain red and white blood corpuscles, epithelium from the kidney hyaline or epithelial cylinders, and, towards the end, pus corpuscles.

Œdema or anasarca, though common in mankind, does not occur in a very marked form, except in intense acute nephritis. Epistaxis is also rare.

=Diagnosis.= The diagnosis requires some care, because unless the urine be examined the symptoms might lead to error. Nevertheless, it is always possible to distinguish between this condition and hæmaturia or accidental renal hæmorrhage.

=Prognosis.= The prognosis is grave, because absolute recovery is rare, and because the condition is very apt to become chronic.

The degree of anuria and the respiratory difficulty are of great service in confirming the prognosis. As soon as urine is freely passed the prognosis becomes more favourable.

=Treatment.= Among the most effective methods of treatment must be included bleeding, which always produces some improvement. Dry friction over the kidneys and flanks, hot moist applications, and the application of a sheep-skin to the loins are also of service. Internally, mucilaginous drinks, diuretic decoctions and milk give the best results. The proportion of albumen rapidly diminishes, dysuria becomes less marked, urine is passed in greater quantities, and in from eight to ten days all the alarming symptoms disappear. Bicarbonate of soda may then be given for a fortnight.

In very grave cases camphor, bromide of camphor, injections of camphorated oil (1 to 2½ drachms internally, or 1 to 1¼ drachms in subcutaneous injections) give excellent results in modifying the pain and moderating the inflammation.

From ½ to 1 drachm of digitalis in powder, or better still an injection of from 5 milligrammes to 1 centigramme of digitalin may also be given when dyspnœa is very great and is accompanied by anasarca. Medicines such as oil of turpentine and considerable doses of nitrate of potash, however, are contra-indicated.

CHRONIC NEPHRITIS

True chronic nephritis, i.e., a condition strictly limited to the renal tissue, and unaccompanied by pyelitis, is still little known among our domestic animals. The symptoms characterising it have not always been carefully noted, and the diagnosis is very often uncertain. Nevertheless, one of the most common forms has been carefully studied by Seuffert, viz., chronic hypertrophic nephritis.

=Causation.= Chronic nephritis is the common sequel to the acute forms, whatever their origin, but it may also occur primarily from repeated chills produced by such conditions as exposure to heavy continued rain when at grass, chills contracted during cold nights and the great variations in temperature in spring and autumn. The conditions, however, thus produced are rather of the nature of subacute nephritis than of chronic nephritis, properly so called.

These forms of chronic nephritis may also occur primarily in consequence of chronic hepatic lesions with pressure on the posterior vena cava, producing blood stasis in the kidneys. Finally, they may represent the delayed effects of slight lesions which have escaped notice and have developed during grave diseases or as a consequence of repeated gestation.

From the anatomico-pathological standpoint, the only conditions hitherto recognised are the chronic hypertrophic forms of nephritis (large, white sclerotic kidney with lardaceous degeneration and sometimes marbling). This is probably because the animals are slaughtered as soon as they suffer in condition, but if they were kept long enough they would undoubtedly suffer also from the atrophic chronic forms of nephritis found in man and in the dog. In the case of man observation has shown that these two forms only represent different stages in the development of one disease, the large, hypertrophied kidney of the early stages afterwards undergoing marked progressive atrophy.

=The symptoms= are at first so vague that diagnosis would be impossible on a single examination. Seuffert states that the condition develops as follows:—

The first sign, loss of appetite, is soon followed by constipation and dull colic, due to congestion of the kidney; the pain is often so great as to cause intermittent groaning.

The urine passed is always turbid, and sometimes blood-stained, but this staining rarely lasts longer than a week. The urine then gradually resumes its normal appearance, is passed in small quantities, and contains more or less albumen. The yield of milk markedly and progressively diminishes.

If treatment is resorted to at this stage laxatives and diuretics appear to effect a real improvement. Unfortunately, however, the apparent improvement is but temporary; the kidneys become hypertrophied, and the right soon occupies the whole of the sublumbar space, its margin extending as far as the extremity of the transverse processes near the anterior angle of the hollow of the flank.

This hypertrophy and the extreme sensitiveness can be detected by external palpation. Internal examination confirms the facts so observed as regards both the kidneys.

The patients eat little and become thin, whatever treatment be adopted. They progressively waste, and die after some months in a state of marasmus, exhausted and intoxicated.

It is very probable that the digestive disturbances are complicated by respiratory and cardiac trouble, as in man and the dog; but neither cardiac nor uræmic disease of the kidney has been recorded.

=Diagnosis.= When the urine is analysed the diagnosis becomes comparatively easy. Persistent albuminuria and hypertrophy of the kidneys during the early stages are significant indications. There can be little hesitation except in so far as pyelo-nephritis and hydro-nephrosis are concerned, but the conditions are distinguished by the character of the urine in the two latter cases, together with the condition of the pelvis of the kidney, and of the ureters.

=Prognosis.= The prognosis is grave, and Seuffert believes that recovery never occurs. This is also true, generally speaking, as regards all forms of chronic nephritis.

=Treatment.= As the disease must be regarded as incurable there is really no justification for treatment. Nevertheless, if for special reasons the owner wishes to keep the animals for a certain time, as in the case of a cow near its time of calving, recourse may be had to the internal treatment suggested in acute nephritis, viz., mucilaginous drinks, diuretic infusions, milk, bicarbonate of soda, stimulating applications to the loins, etc.

HYDRO-NEPHROSIS.

Hydro-nephrosis, i.e., retention of urine in the pelvis of the kidney and in the collecting and secreting tubules, is a somewhat common malady of the bovine species. It is usually confined to one kidney.

=Causation.= Anything which obstructs the discharge of urine through the ureters may cause hydro-nephrosis. Thus, vesical tumours pressing on the orifices of the ureters, calculi which have become fixed in them, torsion or “kinking” of the ureters, may bring about hydro-nephrosis. The urine secreted by the kidney being unable to escape, accumulates in the pelvis of the kidney, in the ureter, and uriniferous tubules, producing dull colic, which escapes observation, or the exact cause of which is not discovered, because the second kidney vicariously acts for the one affected, and urination continues regularly. Secretion continuing in spite of the obstruction, that portion of the ureter above the obstructed point, together with the pelvis and the uriniferous tubules, gradually becomes dilated, until the whole mass of the kidney is hypertrophied.

The ureter sometimes becomes enlarged to the size of a man’s arm, the kidney double, treble, or quadruple its normal side: the interlobular divisions are lost, and each circumscribed lobule soon forms a cystic cavity varying in size. The pressure due to the accumulated urine causes the renal tissue, first the medullary substance and afterwards the peripheral zone, to undergo atrophy.

The kidney is represented by a vast cystic cavity, and the lobules by culs-de-sac; the cortical layer may become atrophied to such a degree as to form merely a fibrous sheath, the primary constituent elements of which are difficult to discover. From 20 to 40 pints of liquid may sometimes be found in the cystic kidney.

=Diagnosis.= The condition is rarely diagnosed, because, as one of the kidneys continues to act, no acute disturbance follows. Only in cases where the cystic kidney projects into the flank are suspicions aroused. Examination per rectum will then permit of the diagnosis being made.

=Prognosis.= Hydro-nephrosis being, as a rule, unilateral, the prognosis is not very grave as regards immediate danger. As the condition is hopeless, however, the lesions being irreparable, the animal should be prepared for slaughter.

=Treatment.= Practically there is no treatment. Puncture of the cystic cavity or even the removal of the hydro-nephrotic kidney certainly suggests itself, but, as such operations are usually opposed to the interests of the owner, they are rarely or never practised.

INFECTIOUS PYELO-NEPHRITIS.

The term “infectious pyelo-nephritis” describes an inflammation which may involve any portion of the mucous membrane of the urinary tract, and which is produced by a special bacillus. As a rule, this inflammation commences in the mucous membrane of the calices and pelvis (pyelitis). It afterwards extends into the depths of the uriniferous canaliculi (nephritis), but in grave and old-standing cases the mucous membrane of the ureters and the bladder may also be affected. The disease had long been known in France (Rossignol, 1848). It was afterwards described in Germany (Siedamgrotsky, 1875; Pflug, 1876), in Switzerland (Hess, 1888), and also in France (Lucet, 1892; Masselin and Porcher, 1895).

=Causation.= Female animals are more frequently affected than males, because the lesions are produced by an ascending infection, originating very frequently in genital infection after delivery. Nevertheless, calculus formation is also an important factor in producing the disease.

Many different agents are capable of producing pyelo-nephritis. Hofflich in 1891 described a bacillus about 2 to 8 micromillimètres in length, which stained readily with aniline colours and with Gram solution. Lucet in 1892 found a short bacillus which did not stain with Gram, and later another thin bacillus which did. Kitt has described cocci, but no other organisms. Masselin and Porcher discovered a cocco-bacillus which stained with Gram and reproduced the disease in an animal lent by Moussu, after a single intra-vesical injection of the culture. Cadéac has met with staphylococci, and Moussu has discovered various bacilli, some resembling the colon bacillus, and pyogenic streptococci.

There is no doubt that many different organisms may produce pyelo-nephritis by ascending infection. The most common seem to be forms of paracoli, such as the Bacillus ureæ. Moussu nevertheless believes that Hofflich’s bacillus, which was rediscovered by Porcher, is that which produces typical pyelo-nephritis. It grows in the bladder without producing cystitis, and is succeeded by an ascending infection of the ureters without causing primary ureteritis, the local inflammation occurring chiefly, it would seem, in the pelvis and the kidney. All the other organisms which Moussu has tested have caused lesions of cystitis and of ureteritis, together with those of pyelo-nephritis.

In these latter cases the pyelo-nephritis assumes the acute form, and is accompanied not infrequently by cellulitis and abscess formation in the tissue around the kidney.

=Symptoms.= Pyelo-nephritis develops in one of two principal forms, the slow chronic form, which is the most frequent, or an acute or subacute form, much more rapid in its development.

The chronic form for a time escapes notice. There is no doubt that at first some general disturbance occurs, such as diminution of appetite, disturbed nutrition, unhealthy general appearance, staring of the coat, tightness of the hide, wasting, etc., but such symptoms are in no wise characteristic, being found in all grave diseases.

The signs only become really significant from the clinical standpoint when the urine appears modified in character, and such modification does not occur until the pelvis of the kidney and the kidneys themselves are already gravely diseased.

The urine is then turbid, of a brownish colour, and charged with sediment, filaments of mucin, pus corpuscles, and earthy phosphates. On analysis it is found to contain more or less albumen.

At a late stage it may even become glairy, blood-stained, or of the colour of blood, and when the pelvis or the calices of the kidney are ulcerated may, on standing, deposit considerable quantities of red blood corpuscles.

Exposed to the air, the urine rapidly assumes a brown tint and smells strongly of ammonia.

Percussion of the loins in the region of the kidneys causes pain, as does external palpation by the flank. On rectal examination at this period the ureters are found to be distended and hard, and they give the impression of rigid or bosselated fibrous cords, sometimes as large as a child’s arm. The corresponding kidney, often both kidneys, are enlarged, sometimes to double or treble their normal volume, and are painful on pressure and fluctuating, at least in the region of the pelvis. On vaginal examination the meatus urinarius is usually found to be inflamed, rough and turgid.

In this condition the animals rapidly lose flesh, the appetite becomes irregular, the general condition gradually gets worse, and they die as a result of continued uro-septic fever or uræmic troubles.

The acute form takes a much more rapid course, with fever, more marked general disturbance, acceleration of pulse and breathing, the passage of turbid and sometimes purulent urine with a strong ammoniacal smell. Pyo-nephrosis is the most frequent and characteristic end. Ordinary chronic pyelo-nephritis may also occur in these cases, and the acute course may be determined simply by accidental ascending infections.

=Diagnosis.= During the early stages diagnosis is extremely difficult, unless a careful examination of the urine be made. Afterwards it becomes easy, the appearance of the urine and the indications furnished by rectal exploration being perfectly characteristic. In very exceptional cases there may be some doubt, as where the urine remains normal, in spite of hydro-nephrosis, or where there is old-standing hæmaturia or renal tuberculosis. In simple hæmaturia the lesions are confined to the bladder and ureters, the kidneys not being affected, and in renal tuberculosis the diagnosis can always be confirmed by the use of tuberculin.

=Prognosis.= The prognosis is extremely grave, for the lesions produced are irreparable, and, moreover, local intervention is impossible.

=Treatment.= There is no curative treatment. All that is possible is palliative treatment with the object of facilitating the function of the kidney and of disinfecting the urinary passages by administering antiseptic substances which are excreted by the kidney. It is not possible, however, to administer active drugs of this kind (e.g., combinations of carbolic acid). As the kidney acts badly it soon ceases to eliminate such substances, and the condition would not be improved, but aggravated.

Benzoate of soda in doses of 2 to 2½ drachms per day dissolved in diuretic liquids is the most useful drug, and sometimes holds the disease in check for a sufficient time to allow of the animals being fattened.

Treatment also comprises certain prophylactic precautions. As the infection which produces pyelo-nephritis originates in the genital tract, it is desirable to protect all animals in a receptive condition (those about to calve or having recently calved) from infection; hence, when the disease is detected in a cow-shed, the patients should be isolated, and the shed thoroughly disinfected.

SUPPURATIVE NEPHRITIS AND PERINEPHRITIS.

Suppuration of the kidney may occur under two conditions. In the majority of cases such suppuration occurs as a complication of pyelo-nephritis; less frequently it is the consequence of infection from within or infection of adjacent parts, leading to the formation of an abscess.

When it results from an ascending infection the kidney becomes swollen, congested and inflamed, and soon displays localised minute hæmorrhages. Pus then forms within the calices, in the large straight tubes, and diffuse suppuration invades all the uriniferous tubules. The enlarged kidney is yellowish, firm under the knife, and when sections are compressed pus exudes from the openings of the tubular canaliculi.

When suppurative nephritis has resulted from accidental infection of internal origin, an abscess is found to have produced more or less extensive atrophy of a portion of the kidney while not affecting the rest of the organ.

It is only in those favourable cases where the renal abscess opens into the pelvis that suppuration may invade the whole of the kidney, producing diffuse suppurative nephritis by secondary infection of the uriniferous tubules. Such complications are rare. Usually the abscess empties through the pelvis, and recovery may occur.

More frequently suppurative pyelo-nephritis develops, together with ureteritis, cystitis, dilatation of the ureters, dilatation of the pelvis of the kidney, and dilatation of the collecting tubules of the pyramids, the final stage resembling the lesions of pyo-nephrosis.

Perinephritis and perinephritic cellulitis, i.e., inflammation with or without abscess formation in the connective tissue and adipose layer surrounding the kidney, always occur in cases of suppurative nephritis or pyelo-nephritis. Such inflammations may also, in exceptional cases, follow direct mechanical injury, but they almost invariably represent complications, the organisms infecting the kidney passing through the tissues and the layer of fibrous tissue, or extending by the lymphatic paths, finally attaining the fatty tissue surrounding the kidney and there undergoing multiplication. The fatty tissue is infiltrated with reddish serosity, is inflamed, and may become the seat of large abscesses communicating with or separate from the abscesses of the kidney itself.

=Symptoms.= Suppurative nephritis is characterised by fever, loss of appetite, arrest of rumination, and frequent attempts to urinate. These attempts are painful, are accompanied by groaning, and end in the passage of an insignificant quantity of blood-stained and purulent urine.

Palpation, more especially palpation of the right flank, percussion over the region of the loins, and examination of the kidneys through the rectum are painful. Wasting is rapid.

If the suppurative nephritis develops rapidly, and particularly if it be accompanied by perinephritis, the patients refuse to rise and appear to be suffering from paraplegia, although not really so, both sensation and motor power persisting in a greater or less degree. Probably the condition is accompanied by reflex pain and irritation of the nerve trunks of the lumbo-pubic plexus.

On the other hand, when suppurative nephritis tends to develop slowly and assume a chronic form, lesions of pyo-nephrosis gradually develop, and are identical in appearance with those of hydro-nephrosis, except that the ureters, the pelvis and the dilatations corresponding to the lobules, are filled with pus.

=Diagnosis.= The diagnosis is not very difficult. The urinary trouble and the composition of the urine itself always arouse suspicion. The diagnosis is confirmed by careful and methodical examination per rectum; the inflammation of the fatty tissue surrounding the kidney can usually be detected.

=Prognosis.= The prognosis is extremely grave, and almost always fatal, particularly in cases of diffuse nephritis.

=Treatment.= No curative treatment can be absolutely relied on. Treatment, if attempted, is limited to the methods suggested for pyelo-nephritis. Mucilaginous, emollient, and diuretic drinks, and daily doses of 2 to 3 drachms of benzoate of soda given in the drinking water, cause some improvement.

Stimulation of the region of the loins also undoubtedly has a favourable effect, and should always be practised, particularly where perinephritis is developing. It may check the course of the disease and prevent the formation of abscesses. On slaughtering animals suffering as above described the layer of tissue surrounding the kidney is found to be lardaceous and fibro-fatty.

Any treatment through the bladder is contra-indicated, for even the passage of a catheter may cause severe injury of the urethra or the vesical mucous membrane and produce a fatal aggravation.

If these conditions are diagnosed early, while the function of the kidney is more or less preserved, and if the animal is still in good condition, it should be slaughtered.

THE KIDNEY WORM (SCLEROSTOMA PINGUICOLA) OF SWINE.

Footnote 7:

From Report of the U.S.A. Bureau of Animal Industry, 1899, p. 612. (Louise Taylor.)

In the United States of America a worm is frequently found in the fat surrounding the kidneys of pigs, and is supposed by farmers to be the cause of paralysis of the hind limbs.

This so-called kidney worm of hogs (Sclerostoma pinguicola) should not be confounded with the kidney worm (Dioctophyme viscerale) of dogs and man. Both of these parasites belong to the same zoological family (Strongylidæ), but to different subfamilies and genera. The kidney worm of dogs grows to a length of 1 to 3 feet. The kidney worm of hogs is much smaller, attaining at most something less than 2 inches in length.

The body of the worm is plump, mottled in color—red, yellow, white, black—according to the organs visible beneath. The average female is about 37 mm. and the average male 32 mm. in length. The worms seem to occur in pairs, usually in cysts or canals; thus, upon the examination of two kidneys with their surrounding fat, fifteen specimens were found, seven males and eight females. The connective tissue layers between the fat were found to be the most general seat of infection, and the cysts were numerous and closely packed together. Although a cyst usually contained two worms, a male and a female, sometimes three were found together, two females and one male, or just as often one female and two males. The cysts contained pus, which bathed the parasites, and in which were thousands of eggs in the segmentation stage. Still, other cysts, upon being cut into, were found without parasites and in a necrotic condition.

It will be noticed that Sclerostoma pinguicola is colloquially known as the kidney worm. In no case, however, has Miss Taylor found it in the kidney substance, but only in the tissue surrounding this organ; the lard appears to be its normal habitat, at least.

Just how the eggs leave the kidney fat or enter the bodies of fresh hogs has not been demonstrated, but it does not seem unreasonable to suppose that they eventually find their way out with the urine. Indeed, Dean reports eggs found in the urine. From analogy one is led to believe that no intermediate host is required, but that in all probability the embryos develop for a short time in water, casting several skins, and they eventually gain access to the hogs either through contaminated drinking water or food.

Because of the hog’s habits, it is difficult to see any practical measures which can be adopted to prevent infection. Feeding from troughs and supplying plenty of pure drinking water will decrease but not exclude the disease. Leuckart’s advice to the Germans, “Swine should be kept in a less swine-like manner,” holds good in all countries and in connection with all diseases. It is equally impossible to suggest practical methods of treatment. This is all the more true because it seems probable that a number of distinct complaints are popularly grouped together by the farmer as kidney-worm disease.