“TREMBLING,” OR LUMBAR PRURIGO, IN SHEEP.
The above term is applied to a disease peculiar to sheep, and characterised by neuro-muscular disturbance, which always ends fatally after a longer or shorter period.
Symptoms. Clinically the disease occurs in two forms, one termed the convulsive form, the other the pruriginous form. In the convulsive form the patients rapidly lose appetite, soon appear unable to stand, fall on their sides, and exhibit spasmodic contractions of certain groups of muscles. After a time the clonic contractions may give place to persistent rigidity. The patients are carried off rapidly in a week or two without other important symptoms. This disease appears to exhibit certain analogies with louping-ill, but these do not seem to be recognised in France, where it chiefly occurs.
In the pruriginous form the beginning of the attack is obscure, and only the shepherd is able to note anything unusual. The animals move in a jerky way, the hind limbs being lifted at times after the manner of a horse suffering from stringhalt. They are excitable, exhibit trembling movements when touched, with convulsive movements of the head, and present an anxious and vacant appearance. The development of these symptoms, which constitute what may be termed the first phase of the disease, is sometimes prolonged, and in winter may last from one to two months. In summer it rarely lasts longer than a week or two.
At this stage a special pathognomonic symptom develops, viz., intense and permanent pruritus of the hind quarters, which causes the animals to rub the croup against any projecting objects, walls, mangers, etc. They thrust themselves backward against the object, and rub with such violence that the wool is torn away and the skin itself often excoriated, although the irritability appears to be in no wise diminished thereby. In the fold the animals sometimes rub against one another, making their sides raw, and bite themselves on the croup, the quarters, and the tail.
When the affected parts are touched with the hand, peculiar movements of the head and the lips are immediately excited, similar in character to those caused by mange. Up to this time the animals continue to feed, but they progressively lose condition, become weak in the hind quarters, and fail to keep up with the other animals in the flock. Their gait becomes hesitating; they move with a trotting step and appear semi-ataxic.
All these symptoms develop without fever, but become aggravated from day to day, until they end in paraplegia and death. This second phase lasts for a period of from two to four months in winter.
Lesions. No lesions can be detected on a simple examination of the dead bodies. Gilbert has mentioned a change in the blood; Trasbot, chronic inflammation of the pia mater and of the lumbo-sacral portion of the spinal cord. German writers have described sclerotic changes in the posterior portions of the cord. Moussu has carried out a large number of examinations, but has never found these lesions, either on anatomical or on histological investigation, and he considers that they are not by any means present in all cases.
Besnoit and Morel, who carried out a very remarkable anatomical and pathological study of the disease, used Nissl’s staining method, but only found very discrete changes in the cord (vacuoles in the motor cells of the anterior horns). They found, however, significant lesions of neuritis in the peripheral nerves.
Causation. The cause is as yet little understood, and it is difficult to prove how the forms of neuritis described by Besnoit are brought about.
The disease was not known in France before the introduction of Merinos, and former investigators referred it to heredity, consanguinity, precocity, and even to sexual excitement. German writers declare that it seems more particularly to attack rams and the better-bred varieties. In reality, the disease occurs in all flocks, and in all kinds of sheep indiscriminately; it attacks ewe lambs and young castrated lambs as well as rams. Moussu is absolutely of this opinion, and for want of more precise information agrees with Trasbot, and, he believes, with Besnoit, that the symptoms shown may possibly be referred to a chronic intoxication.
Diagnosis. The diagnosis is difficult during the early stages, but when the pruritus becomes manifest there can no longer be room for doubt.
Cases of paraplegia might perhaps be mistaken for paraplegia due to cœnurosis, but in the latter case there is no pruritus.
Prognosis. The prognosis is extremely grave, observation having shown that all the patients die after a longer or shorter time.
Treatment. Until now treatment has proved absolutely useless, and it would seem the best course to slaughter the animals before wasting becomes marked.
SECTION VI.
DISEASES OF THE PERITONEUM AND ABDOMINAL CAVITY.
CHAPTER I.
PERITONITIS.
Peritonitis, i.e., inflammation of the peritoneum, may attack any of the domesticated animals. It must, however, be regarded as an almost accidental and relatively infrequent disease. It is due to infection of very varying character, and from the clinical standpoint may assume one of two forms—acute peritonitis or chronic peritonitis.
ACUTE PERITONITIS.
The microorganisms which produce peritonitis have not been the subject of special investigation in the domesticated animals, though the colon bacillus and streptococci, so frequently found in the female genital tract after parturition, seem to be the most frequent causative agents. Certain putrefactive organisms may also bring about the disease.
The peritoneum may become infected, and acute peritonitis ensue under various circumstances.
All operations in which the peritoneal cavity is opened, such as castration of the cow and of the sow, laparotomy, gastrotomy, enterotomy, etc., may be followed by acute peritonitis if performed without sufficient regard to aseptic precautions. Peritonitis then usually assumes an acute septic form.
Even simple puncture of the rumen, though usually quite harmless if carefully performed, may by followed by local or general peritonitis should food material escape from the rumen and find its way into the peritoneal cavity.
One of the most frequent causes is infection from the genital tract soon after parturition. Here the agents of infection are not introduced directly into the cavity, but find their way there in consequence of a diseased condition of the mucous membrane and the uterine walls. Ascending infections of this character and infections by contiguity of tissue may only give rise to local peritonitis, though in too many instances they become generalised.
Acute peritonitis may follow infection from the stomach or bowel, should a foreign body perforate the rumen or reticulum and pass backwards towards the peritoneal cavity, or a serious intestinal inflammation (enteritis, invagination, etc.) facilitate the passage of microbes through the thickness of the intestinal wall.
Abscess of the liver, suppurative echinococcosis, renal infection, pyelo-nephritis, acute cystitis, rupture of the bladder, etc., may in a similar way become complicated with acute peritonitis.
Finally, abdominal wounds may cause interstitial ruptures and lesions in the serous membrane, accompanied by local exudation (kicks, horn-thrusts, blows from cart-poles, etc.), and if microbic agents are brought within the region of the lesion by the general circulation or otherwise, peritonitis may follow.
Symptoms. At first the symptoms are vague and imperfectly defined, and diagnosis is always very difficult during the first few days, except in cases where there exists a lesion or a condition previously recognised as likely to become complicated with peritonitis.
The early symptoms comprise fever, loss of appetite, arrest of rumination, rigors, constipation, etc., but these symptoms only attain full significance when accompanied by what has been termed “peritonism.”
The patient appears to be suffering from tympanites, as may really be the case, but the tympanites of the rumen and gaseous distension of the loops of bowel are not primary, and only result from the arrest of peristalsis. The primary condition is peritonism, i.e., distension of the peritoneal cavity, this being indicated by a symmetrical fulness of the right and left flanks.
The patients suffer from dull colic, and from this time always assume an attitude indicating pain. They remain in one position, with the back arched, the limbs gathered together, and the lower abdominal wall shortened. The face expresses suffering, the respiration is short and rapid and of the costal type, movement is painful and causes groaning, and the animals do not shrink when the lumbar region is pressed upon.
Palpation of the abdomen causes pain, and if practised at certain points may be followed by groaning. This method of examination, however, gives no further information, because the abdominal wall is rigid, tense, and as though tonically contracted.
Percussion is followed by tympanic resonance in the right and left upper zones, due to accumulation of gases of fermentation, and to distension of the peritoneal cavity itself. Towards the lower parts, however, percussion produces a dull sound. The presence of liquid can here be detected by the manner in which impulses are transmitted, particularly at the period of crisis and when much exudation exists.
Abdominal auscultation shows that the digestive movements are arrested. Peristaltic movement ceases, and the movements peculiar to the rumen and to the progress of food through the intestine are absent. Fermentation sounds, however, can be detected.
The heart beats are strong, rapid and violent, and yet the pulse remains feeble, though the artery is tense.
At a later stage, when the disease becomes aggravated, pain is less acute, depression is extreme, the animals no longer even drink, the abdominal wall becomes relaxed, and diarrhœa is succeeded by constipation. Palpation of the abdomen is less painful and does not cause groaning, but the pulse becomes feebler, much more frequent, imperceptible, and at last the animal dies from intoxication and exhaustion, caused by the fever and pain.
When peritonitis is due to rupture of the intestine or escape of alimentary material from the rumen into the peritoneal cavity, as may occur after puncture of the rumen or gastrotomy, etc., fever is not always very marked. The temperature may even fall below the normal point. Some cases vary greatly from the type described as regards their development, but the important features are always present, and the difference is chiefly found in the course of the disease.
Diagnosis. The diagnosis is rather difficult, but when there is colic, together with persistent peritonism, exaggerated sensitiveness to palpation and arrest of the functions of the digestive apparatus, there is little room for doubt.
Prognosis. The prognosis of acute peritonitis is very grave.
Lesions. The lesions vary with the primary cause (traumatism, metritis, suppurative echinococcosis, foreign bodies escaping from the digestive tract into the peritoneal cavity, etc.).
The parietal and visceral layers of the serous membrane are always inflamed, vascular, roughened, dull, and in places covered by vegetations. Between the loops of intestine and in the peritoneal pockets there are discovered more or less numerous and more or less thickened false membranes, presenting the characteristics of the false membranes seen in acute pleurisy.
The liquid varies in quantity and in colour, being sometimes lemon-yellow, sometimes purulent, sanguinolent, or even blackish, and of putrid odour.
The lesions may appear more marked at a particular point, such as the uterus, rumen, hypochondrium, etc., and the intestinal loops may become partly fixed in position by false membranes. In time these false membranes may solidify and undergo transformation into fibrous tissue.
Treatment. Treatment is generally useless in cases where peritonitis results from rupture of the bladder or intestine or from eventration. Complete and perfect cleansing of the infected abdominal cavity is impossible in large animals.
In other cases the animals should be left completely at rest, and purgatives should be avoided. Movement or the administration of purgatives provokes peristalsis, and, as a consequence, almost inevitably leads to generalisation of a lesion which might otherwise have some chance of remaining localised, as in pelvi-peritonitis and peritonitis due to foreign bodies issuing from the rumen or reticulum. If the movements of the intestinal loops disperse the septic liquids beyond the points originally injured, the whole cavity becomes inoculated and generalised peritonitis is set up.
Emollient and diuretic drinks containing opium, and oatmeal or linseed gruels, have the advantage of soothing the colic and preventing stagnation in the bowel. These should be given from the first and solid food entirely avoided.
The sides of the abdomen should be mildly stimulated, provided the operation does not give rise to undue pain and cause the animals to struggle. Vesicants are preferable to mustard, though mixtures of mustard and linseed meal may be used, and, if found advantageous, can be repeated.
Mercurial salts, though much used in earlier times, are now entirely given up. Diuretics, such as bicarbonate of potash, nitrate of potash, alcohol, and acetate of ammonia, should be used, according to circumstances.
Aseptic washing out of the peritoneal cavity would be advantageous, but in large animals cannot easily be effected.
CHRONIC PERITONITIS.
Causation. Chronic peritonitis may occur as a termination of the acute form, but it may also develop gradually as a result of disease of the kidney (pyelo-nephritis), of the uterus or ovaries (chronic metritis, tumour of the ovary), of the liver (suppurative echinococcosis), or of any other lesion in neighbouring parts which is capable of setting up continued irritation.
It also accompanies tuberculosis of the peritoneum, cancer of the peritoneum, chronic disease of the bladder, etc. Further, it appears, but more rarely, in certain chronic diseases, such as chronic dysentery and lymphadenitis.
Lesions. The lesions consist of local thickenings of the peritoneal layers, and numerous papilliform vegetations scattered very irregularly over the parietal peritoneum, mesentery, epiploon, etc.
If the disease has existed for a long time, fibrous bands or solid adhesions may be discovered, connecting various parts of the digestive apparatus with one another, or with the abdominal walls.
Sometimes the intestinal contents seem almost entirely adherent to the abdominal walls.
The primary lesions of the liver, spleen, kidneys, or genital organs, from which the disease originated, are also found.
The quantity of exuded liquid varies greatly; sometimes there is a great quantity of a transparent or lemon-coloured liquid, resembling that of ascites. In other cases the liquid is scanty, and may be confined between layers of bowel, which are connected by an inflamed layer of epiploon.
These old-standing lesions cause atrophy of the abdominal organs, contraction of the intestine, and sometimes true obstruction.
In chronic tuberculous peritonitis the adhesions between the intestine and the abdominal walls may be enormous. The peritoneum is generally covered with great masses of tuberculous new growth, while the mesenteric and sublumbar lymphatic glands are attacked.
Symptoms. The disease develops without marked fever or grave interference with the chief functions, and the first approach of the disease may, therefore, easily be overlooked. Chronic peritonitis, moreover, may remain strictly localised.
When the disease assumes the ascitic form the dominant sign is readily detected. Where new membranes form the principal lesions the symptoms are much less definite, and the existence of disease is chiefly indicated by digestive disturbance, such as diminished peristalsis, the occurrence of colic, diarrhœa, etc.
It is well to remember, however, that these troubles often follow an ascitic stage, which may gradually disappear owing to the fluid becoming absorbed. Even in the fibrous form, where the intestines appear completely glued together by adhesions, the volume of the abdomen is increased and the belly is deformed, as in ascites.
In time patients suffering from primary lesions of an important internal organ are affected in their digestion, lose flesh and become anæmic, and finally cachectic.
Diagnosis. The diagnosis is by no means easy, particularly in the fibrous forms, owing to the great difficulty of discovering the primary lesion.
Prognosis. The prognosis is grave, though it must not be regarded as necessarily fatal. In cases resulting from genital diseases, and in localised chronic peritonitis resulting from persistent, but not excessive, mechanical violence, complete and perfect recovery may occur.
On the other hand, in cases of chronic lesions of the liver, kidneys, heart, etc., and in tuberculosis, carcinoma, etc., recovery cannot be expected.
Treatment. Treatment should be directed towards combatting the chronic inflammation. With this object resort may be had, when necessary, to persistent stimulation of the sides of the abdomen, mild blisters and mustard plasters, or friction with turpentine.
The food should be easy of digestion, and of first-rate quality. The most useful drugs comprise mild, unirritating diuretics, general stimulants, and tonics.
Animals affected with incurable lesions should not be treated.
ASCITES.
True ascites consists in dropsy of the peritoneum, unaccompanied by inflammation of that membrane, or by the presence of infectious microorganisms in the transuded liquid. Properly speaking, it is not a morbid entity, but only a symptom common to several very complex diseases.
Causation. The diseases which produce it may be set forth under five principal heads:—
(1.) Cardiac affections in general, particularly chronic lesions of the heart, interfering with venous circulation, and causing prolonged stasis of blood in an organ or tissue.
(2.) Pericarditis due to foreign bodies, and the various forms of pseudo-pericarditis, i.e., lesions in the neighbourhood of the heart, causing compression of that organ and of its vessels.
(3.) Generally speaking, all lesions which interfere with the return circulation, particularly lesions of the liver (distomatosis, echinococcosis, and interstitial hepatitis). These produce compression of the portal vein or other obstacle to circulation, and the transudation is exclusively localised in the abdominal cavity. The connective tissue does not become infiltrated.
(4.) Diseases of the kidneys (nephritis, pyelo-nephritis), which secondarily produce cardiac disturbance.
(5.) Gestation, which causes compression of certain digestive viscera, and of certain veins of the pelvic cavity.
Ascites was formerly regarded as always forming a complication either of anæmia or of hydræmia. We now know that the primary cause of these three collections of symptoms (ascites, anæmia, and hydræmia) is the development of certain chronic wasting diseases or chronic lesions of the heart, liver, and kidney, which act and react upon each other.
Symptoms. True ascites is unaccompanied by fever. The condition develops slowly, insidiously, and therefore escapes notice at first. Only when the exuded liquid is present in considerable quantities is the condition apparent. The symptoms are similar to those of ascites following chronic peritonitis.
The transuded liquid progressively accumulates in the peritoneal cavity, the lower portion of which it distends. When the animal is viewed from behind the enlargement appears symmetrical, despite the position of the rumen. The intestinal contents float on the liquid and are thrust upwards towards the lumbar region. On palpation, the abdominal cavity seems unusually full, the tension differing in proportion to the quantity of liquid. The accumulation of liquid may become considerable and interfere with respiration, circulation, and movement. Very marked anæmia always exists, the mucous membranes are extremely pale, the respiration is rapid, the pulse feeble, all these symptoms being consequent on the primary disease of the heart or liver. Percussion of the lower part of the belly produces a dull sound. On the left side this dulness often extends from the linea alba as high as a horizontal line, uniting the external angle of the ilium and the hypochondriac circle. On the right it is bounded by a horizontal line. Percussion or, better still, palpation provokes on one side of the abdomen a wave or impulse of the liquid, perceptible to the touch or even to the view at the opposite side.
Diagnosis. In general diagnosis is easy, thanks to the slowness with which the disease develops.
Prognosis. The prognosis varies in each case, more especially according to the more or less marked debility of the animal. Ascites due to gestation is usually of a very simple character, but if it is the result of pericarditis produced by a foreign body, or of nephritis, the outlook is very gloomy; lesions of the kidney in particular showing little tendency to recovery. Finally, the prognosis varies when the ascites follows disease of the liver, for certain exceptional cases have been noted in which an attack of hepatitis has led to the disappearance of the transudate.
Lesions. The lesions peculiar to this disease are very trifling. Transudation takes place without inflammation of the peritoneum, although the veins of the abdominal cavity are abnormally dilated. The abdominal wall is thin and distended, and the tissues are colourless as though soaked in water. The cavity is distended with a clear lemon-coloured albuminous liquid free from blood corpuscles.
Treatment. The treatment must vary according to circumstances, i.e., having regard to the primary cause. Ascites due to gestation, which is always slight, calls only for simple hygienic treatment; but when the disease is attributable to lesions of the heart, pericarditis, or chronic affections of the kidney or liver, it is generally incurable in common with the original lesions themselves.
If, finally, no clearly defined cause can be detected, or if the ascites is due to chronic peritonitis, treatment should be attempted. The first step may consist in evacuation of the liquid for the purpose of reducing the excessive pressure on the diaphragm and facilitating respiration. For this purpose an aseptic puncture is made with a fine trocar on the right side of the abdomen in the flank region, about equidistant from the umbilicus and the loose flap of skin in front of the stifle. The absorption of liquid may afterwards be assisted by administering diuretics, such as digitalis, bicarbonate of potash or nitrate of potash, and by giving lukewarm drinks, tonics, etc. In Germany injections of pilocarpine have been suggested, but it is doubtful whether they have proved satisfactory.
PERITONEAL CYSTICERCOSIS.
The above name has been given to a parasitic disease caused by the infestation of young animals, such as calves, lambs and young pigs, with embryos of the Tænia marginata of the dog.
Symptoms. Peritoneal cysticercosis is often of so mild a character, and the number of embryos which penetrate the body so small, that in the majority of cases there are no visible symptoms. It is not until the meat comes to be dressed by the butcher that little cysts (Cysticercus tenuicollis) are discovered in the abdominal cavity.
Unfortunately, in exceptional cases it may also happen that the number of embryos in the abdominal cavity is so great as to produce lesions of acute hepatitis, acute peritonitis, and sometimes pleurisy. These grave forms are more common in young pigs and lambs.
The animals appear dull, feeble, exhausted and without appetite, but exhibit marked thirst, lose flesh and become anæmic in a few days. Soon afterwards they show symptoms of acute peritonitis, with exudation of fluid, and death may follow in a week or two.
In cases where infestation is less marked, the animals may exhibit only progressive anæmia, without well-developed symptoms of peritonitis, until death occurs.
Lesions. On post-mortem examination a sero-sanguinolent exudation is seen, together with more or less numerous false membranes, and a varying number of young cysticerci floating freely in the liquid or enclosed in the folds of the mesentery. The cystic vesicles are spherical, ovoid, or elongated, and translucid or opalescent. They are some millimètres in diameter, and in some cases are very numerous, ranging from a few hundreds up to several thousands, but in others comparatively few.
The liver shows signs of intense hepatitis, caused by embryos burrowing into its tissue.
Causation. The causes are limited to a single fact, viz., ingestion of the eggs of Tænia marginata, which are spread over the fields in the excrement of dogs suffering from that parasite.
Diagnosis. The diagnosis can only be arrived at by a post-mortem examination, when cysticerci in various stages of development are discovered.
Prognosis. The prognosis is difficult to indicate, because everything depends on the intensity of the infestation.
Treatment. No curative treatment is possible, direct action on the developing parasites being impracticable. Nevertheless, some patients survive, and after having shown grave general disturbance may gradually improve.
The only efficacious treatment is of a prophylactic nature, as in cœnurosis and echinococcosis. Dogs suffering from tæniæ should periodically be treated and freed from their parasites.
CHAPTER II.
HERNIÆ.[[6]]
[6]. For a fuller description of herniæ and their treatment, see Möller and Dollar’s “Regional Surgery,” pp. 263–309.
CONGENITAL HERNIÆ.
PERINEAL HERNIA OF YOUNG PIGS.
This variety is very common in young pigs, on account of their anatomical peculiarities and of the persistence and enlargement of the inguinal canal. Loops of intestine, impelled by their own weight, accumulate at the lowest point and readily pass into the canal.
It is usually when the little pig begins to eat, i.e., a fortnight or three weeks after birth, that the symptoms become plainly apparent.
The hernia is indicated by a swelling which commences in front of the pubis and extends backwards behind the hind limbs. When the herniated loop of intestine is examined by palpation, the presence of liquid in it can be detected, particularly after a meal, while a characteristic gurgling sound is heard.
Diagnosis. To confirm the diagnosis, the animal is placed on its back, whereupon reduction as a rule is easily effected. As soon as the animal rises again the hernia returns.
The prognosis is not grave.
The treatment is exclusively surgical, and the hernia can be reduced and castration performed at one and the same time. The animal being placed on its back and firmly held, an incision of about 2 to 3 inches in length is made in the inguinal region, dividing the skin and subcutaneous connective tissue only. The vaginal sheath is then completely isolated, the hernia reduced, and a ligature applied to the sheath and the spermatic cord close to the abdominal wall. The testicle is then removed.
If adhesions have been set up, which is quite exceptional, the vaginal sheath is incised and the loop of adherent intestine liberated, when it can readily be returned. The vaginal sheath and spermatic cord are then twisted as high as the level of the inguinal ring and tied with catgut. To prevent this ligature becoming displaced, it should be fixed by passing a sterilised thread through it and through the mass of tissue; the hernial sac should be divided immediately below. In order to ensure greater security, it may even be desirable to pass a suture through the margins of the inguinal ring.
UMBILICAL HERNIA.
Umbilical hernia is less common in young animals of the bovine, ovine and porcine species than in the foal, and when existing almost always disappears at the period of weaning. The rumen then assumes its full development, the loops of intestine are displaced and thrust towards the sublumbar region, and the hernia disappears. The same is true of the young pig, the development of the stomach producing the same favourable result.
In the rare cases where this hernia is not reduced spontaneously, it may be necessary to utilise the methods so frequently employed in the foal, and, despite the number of these, there are only two which can thoroughly be relied on to give good results.
In the first, irritants are employed.
Subcutaneous injections of concentrated solution of common salt, filtered and sterilised, or 10 per cent. solution of chloride of zinc produce enormous engorgement of the connective tissue, which thrusts back the herniated loop of intestine and later causes the development of very resistant fibrous tissue, which prevents the hernia returning.
To ensure this result, however, it is indispensable that perfect asepsis should be observed in the injections, for if germs are introduced severe suppuration occurs at the point of injection. The injections are made at four opposite spots in the subcutaneous tissue surrounding the hernia, 1 to 2 drachms of saline solution being injected at each spot; of the chloride of zinc solution half a cubic centimètre is used. This method is only of value in small herniæ, which may sometimes be cured by the application of sinapisms alone.
The second method is applicable to larger herniæ, and aims at destroying the hernial sac.
The application of clams is simplest, and can be recommended. The patient is placed on its back, reduction is effected, the hernial sac is drawn upwards vertically, and the clams placed as near the abdominal wall as possible, after care has been taken that no portion of the intestine is included in the sac. The clams are kept in place by a suture passed through the neighbouring tissues.
In other cases where a radical cure is necessary, because of adhesions within the hernial sac, the patients are similarly placed on their backs, the hernial sac is opened aseptically, the adherent parts liberated, the herniated portions of intestine reduced, and the hernial ring sutured with sterilised strong silk, the skin being afterwards brought together with silk sutures after removal of the sac itself. A surgical dressing can then be applied to the umbilicus. The patients should be carefully dieted.
When the hernial ring is large and its lips widely dilated, the silk sutures, even when supported by secondary sutures, sometimes cut through the tissues and do not achieve the desired result.
Fig. 222.—Schema illustrating Degive’s operation for umbilical and ventral herniæ. A, Serous; B, musculo-aponeurotic, and C, cutaneous coats of the hernia; D, the special needle in place; EE, clams; FF, nails. The three figures show the successive stages of the operation.
Degive’s method (see “Möller and Dollar’s Regional Surgery,” p. 304) can then be employed. The hernial sac is opened under antiseptic precautions, in order to break down any existing adhesions, and the skin and edges of the hernial ring are transfixed with packing needles about 8 inches long. Above these is adjusted a clam, which is closed, by means of a screw and firmly secured. The packing needles are then replaced with horse-shoe nails, the points of which are bent round. In about a week the necrotic tissue falls away, and recovery occurs even in severe cases in which previous treatment had failed.
ACQUIRED HERNIÆ.
Acquired or accidental herniæ are not serious, and only deserve to be studied in so far as they affect organs contained within the abdominal cavity. They may result from violence, or may occur without the intervention of any external cause.
Traumatic herniæ may occur at any point in the abdominal wall. Under the influence of a violent blow from a waggon pole, a horn thrust, a kick, a fall, etc., the muscular tunic of the abdominal wall is injured and becomes fissured in the direction of its fibres. The peritoneum is rarely affected. Being pushed outwards by the digestive viscera, however, the peritoneum projects into the muscular layer, distends it, separates the layers of subcutaneous tissue, and finally forms a distinct hernia.
The consequent disturbances are more or less marked and the lesions more or less variable, according to the part affected. In the lower region fissure of the abdominal wall affects the rectus abdominis, obliquus abdominis and transversus abdominis, and on the right side gives rise to hernia of the abomasum or small intestine, on the left of the rumen. In the lateral regions muscular fissures can be produced only in the transversus and obliquus abdominis muscles. Hernia of the rumen is rare on the left side. On the right side hernia of the intestine is more readily produced.
In all cases where hernia is suspected, the hernial orifice should be examined. Its situation will at once show which organ is affected.
Spontaneous herniæ are very rare in the domesticated animals. They occur only in aged animals, and various reasons have been suggested to explain their appearance. Certain herniæ of this character are only found in old female animals which have borne a considerable number of young. Repeated gestation produces elongation and relaxation of the muscular fibres from the weight of the fœtus and its envelopes. In time, the abdominal walls become thinner and thinner under the weight of the viscera, and thus facilitate the slow formation of a hernia. Certain practitioners consider that some of these spontaneous herniæ are due solely to the pressure produced by the distended viscera, as for example in greedy-feeding animals. In such cases the weight of the viscera would cause, as in the previous case, a certain degree of anæmia and emaciation of the abdominal muscles.
These spontaneous ventral herniæ are due in reality to changes in the nutrition of the abdominal wall, the exact cause of which it is difficult to ascertain. The elastic tunic becomes atrophied, and ceases to act as an automatic girth; the muscular wall gradually becomes sclerosed from the white line towards the sides, and having lost its elasticity becomes distended and thinned.
These changes are not exclusively caused by old age, for they may be found even in young animals.
Nothing can be done in cases of spontaneous herniæ. The qualities originally pertaining to the abdominal wall cannot be restored, and treatment is confined to applying suspensory bandages, and, where possible, preparing the animals for slaughter.
HERNIA OF THE RUMEN.
Causation. Hernia of the rumen is, as a rule, of traumatic origin, and always occurs in the left flank, either in the lower or middle regions. Cases of spontaneous hernia of the rumen have been observed in very old and anæmic animals, as well as in females which have borne many young and which have suffered from spontaneous progressive hernia of the uterus.
Symptoms. The symptoms are the same in all herniæ. Immediately after the injury the abdominal organs show a tendency to escape in the direction of least resistance. A fold of the rumen passes through the muscular fissure, and a swelling soon becomes visible externally, which alters the contour of the abdomen. Most frequently at this time traces of the injury can be detected on the surface of the skin, either the linear trace due to a horn thrust, the ill-defined lesion due to a kick, or what not. There follows rapid swelling, which results from the inflammatory reaction due to rupture of small vessels within the muscle. A certain amount of sanguineous exudation and of œdematous swelling occurs, and may at first suggest the existence of an abscess of the abdominal wall. At the same time there is more or less fever, which may continue for a few days, but the swelling seldom lasts very long; in two or three days even, it becomes reabsorbed, commencing at the upper part and diminishing progressively downwards.
Henceforth the hernia alone remains.
It is soft, compressible, and sometimes susceptible of reduction. On palpation, the operator feels a rupture extending through the tunic and the abdominal wall, sometimes even through the muscular tissue of the rumen, in cases where the skin is neither perforated nor torn through. The mucous membrane of the rumen is rarely ruptured.
Whether or not the peritoneum is injured, the rumen presses between the lips of the wound, thrusts back the skin, and separates the connective tissue, thus setting up local irritation and œdematous swelling. The rumen may contract more or less close adhesions with the abdominal wall, and even with the subcutaneous tissues.
Afterwards, when the exudate has been reabsorbed, palpation reveals a different condition of things. The mass is uniformly fluctuating or semi-fluctuating, and is surrounded at the base by an indurated ring of very varying dimensions. The final indication—which, however, is not invariably seen—deserves attention, viz., the change in volume of the hernia at different moments, particularly during meals. This change in size only occurs if the hernial orifice is large.
In cases of spontaneous hernia of the rumen, the condition is not fully established at first. It is always progressive, and the lesion is situated in the lower abdominal region. It increases in size from day to day, from week to week, whilst the animals lose appetite and flesh. Spontaneous herniæ are never accompanied either by exudation, engorgement, fever, or traces of mechanical injury.
When only slightly developed, herniæ do not threaten life, a fact which often prevents the owners troubling about them. Progressive herniæ may become of considerable size, and two cases are recorded in one of which the opening of the hernial sac was 13½ inches in length and 18 inches in width, and in the other 28 inches in length and 24 inches in width. The latter is the largest ever recorded.
Complications. Complications are not always grave. If the hernia is little marked the function of the rumen is not greatly affected and its rhythmic contraction continues. When the original injury has caused rupture of the muscular tissue of the rumen, and the mucous membrane has passed into the opening, it may become strangulated and gangrenous.
Finally, if the mucous membrane has been torn at the same time as the muscular tissue (which is very uncommon), alimentary material may escape into the subcutaneous connective tissue, setting up either cellulitis and death by infection, or suppuration; abscess formation and rupture towards the exterior, followed by a persistent sinus; or again septic peritonitis, and death.
The same results may occur when the hernia is in a very low portion of the abdomen; food accumulates in it, becomes stagnant there, sets up local irritation and inflammation, and sometimes abscess formation with external discharge, followed by fistula of the rumen.
Gastric fistula without secondary complications is compatible with life, and even with fattening for slaughter, provided the peritoneum covering the rumen becomes attached to the opposing surface of peritoneum around the perforation. The fistula is then surrounded by a circular mass of fibrous tissue, forming a kind of sleeve.
Lesions. The lesions are the same in all herniæ. They consist primarily in rupture of the abdominal wall, and, later, of sero-sanguinolent infiltration of the margins of the wound, similar to that accompanying the formation of an abscess. Hernial swellings are of very varying size. Apart from cases similar to those above described, the swelling may be simply an inch or two in diameter, or it may attain the dimensions of a hen’s egg or even of a man’s fist.
When the abdominal tunic only has been ruptured, as is most frequently the case, the peritoneum is thrust outwards and forms a cavity, the hernial sac. This sac is absent when the peritoneum is ruptured. Little by little the surrounding connective tissue forms a pseudo-serous hernial sac. But, nevertheless, in some cases there may be found, immediately under the skin, the mucous membrane of the rumen in a state of congestion and ready to become gangrenous.
Diagnosis. Easy in all cases.
Prognosis. Very variable. In the case of small herniæ situated in the lateral regions of the abdomen the prognosis is not very grave. If, however, the rupture is wide, and situated in the lower portion of the abdominal walls in a dependant position, the hernial swelling steadily grows in size in consequence of the weight of the food which is constantly thrust in this direction by the contraction of the rest of the rumen, and recovery is impossible. The only resource is to fatten the animals as quickly as possible for slaughter.
HERNIA OF THE ABOMASUM.
Causation. This condition is due to causes similar to those above mentioned, including mechanical violence. It is rare in adults, but much commoner in young animals, especially in sucking calves, where the abomasum is the most highly developed digestive compartment.
Hernia of the abomasum is produced essentially and almost exclusively by horn thrusts inflicted when calves attempt to suck cows other than their own mothers.
Symptoms. Hernia of the abomasum always occupies a certain position in the lower part of the right flank, or, rather, in the space comprised between the white line and the lower part of the circle of the hypochondrium.
The immediate symptoms are similar to those of hernia of the rumen. They include: progressive swelling, formation of a peripheral œdematous ring, interstitial sero-sanguineous exudation, which becomes absorbed after a few days; finally, the development of a hernia, formed as a rule by the larger curvature of the viscus, which is in direct contact with the abdominal wall.
The lesions are those common to all hernia, and usually include a partially healed wound.
Diagnosis. The diagnosis is easy, particularly in calves, and the possible existence of the condition should always be borne in mind when dealing with injuries of the right pre-umbilical zone. An abscess of the lower abdominal wall may occur at or near the umbilicus as a result of omphalitis or umbilical phlebitis, but it is readily distinguished from a hernia.
The prognosis is graver than in the case of hernia of the rumen, for the displacement of the abomasum interferes with its regular function. The prognosis varies, however, in accordance with the size of the hernia. If the rupture is small, there is some chance that the abomasum, on account of its longitudinal position, many penetrate but slightly into the fissure.
If, on the other hand, the rupture is large, the prognosis becomes very serious. It is sometimes best to slaughter the animal, if in good condition; otherwise an operation is necessary.
HERNIA OF THE INTESTINE.
Causation. This is due to the same cause as hernia of the rumen—a blow which, while injuring the skin only to a trifling extent, damages the abdominal walls, and even the intestine itself.
Symptoms. The hernia is situated in the lower or lateral zone of the right flank.
The symptoms present some peculiarities. The loop of intestine which has passed through the aperture in the abdominal walls becomes distended by the accumulation in it of semi-liquid alimentary material, and, acting by its own weight, produces a hernial sac, which steadily grows in size. The skin being very mobile, and the subcutaneous connective tissue very loose, they readily yield and become separated. The inflammatory symptoms disappear, and are followed by a swelling under the skin, which is compressible all over, and can readily be reduced, whereupon it gives forth a gurgling noise, or a sound as of borborygmus. Reduction is easier when the animal is lying on its left side, or on its back.
Complications. Strangulation of the small intestine is the only serious complication in this form of hernia, but it is very dangerous. It occurs frequently when the rupture is somewhat highly-placed on the lateral portion of the abdominal wall, because the loops of intestine have a tendency to descend, thrusting away the skin owing to the weight of material which they contain.
The partially digested food is apt to accumulate in the herniated loop, and hernial engorgement, the first phase of strangulated hernia, rapidly occurs.
Fermentation is set up in the half-digested food, and putrid gases are generated. Thus the hernial sac becomes distended, the vessels are compressed, circulation is arrested, and gangrene supervenes.
At this time gurgling sounds and a certain degree of tympanitic resonance may be noted. These are followed by all the symptoms of intestinal strangulation—namely, intense colic, which suddenly disappears when the intestine becomes mortified, absolute loss of appetite, stoppage of rumination, constipation, suppression of defæcation, tympanites, and peritonitis.
The diagnosis is comparatively easy at an early stage, owing to the peculiar character of the soft swelling, which is easily compressible. At first there may be difficulty in distinguishing it from a collection of serous fluid, but the facility with which the swelling can be reduced removes any doubt.
The prognosis is always serious, on account of possible complications, due to strangulation of the herniated loop. When the hernia is chronic, reduction is much more difficult, there being, as a rule, adhesions between the intestine and the hernial sac.
TREATMENT OF HERNIÆ.
Numerous attempts have been made to treat abdominal hernia in bovine animals.
Irritant and vesicant applications to the skin have been recommended, with the object of producing a large swelling, and thus thrusting back the herniated mass into its proper position.
One of the most popular of these applications is nitric acid of a strength of 36° Baumé, applied to the skin twice at an interval of ten days. Skilfully used, it gives good results in umbilical herniæ, but its effects in ventral herniæ are less certain. It causes slow mortification of the skin, abundant subcutaneous swelling, and produces an eschar, which separates in about a fortnight.
An ointment of yellow chromate of potash (1 to 8) has been recommended, and can be applied two or three times at intervals of eight or ten days.
Bandaging and various forms of local dressing have also been employed from time to time. Serres employed simple bandages similar to those used in cases of inguinal or crural hernia in human beings. These bandages have a pad, which is applied over the hernial opening, but their action is strictly palliative. They simply allow of the animal being kept a certain length of time for fattening.
When the hernia has been reduced recourse may be had to bandages saturated in melted pitch, care being taken to extend the dressing a considerable distance beyond the limits of the hernial opening. Successive layers of bandage are superposed across and across, and, to make the dressing more solid, the pads may be reinforced with a sheet of solid cardboard. This method only succeeds when the swelling is slight and is situated elsewhere than in the lowest portions of the abdomen.
Some practitioners prefer a cloth bandage after reduction. The bandage is ten to fifteen yards in length, and should be considerably wider than the greatest measurement of the hernial opening. Such bandages can easily be applied to calves, whose bodies are of regular shape, but in adults, in which the body is of ovoid formation, they prove faulty, and tend to slide backwards or forwards.
All these measures are merely more or less palliative and of temporary effect.
The only rational and radical treatment is surgical. This is clearly indicated when the hernia is recent and of small size. At a later stage, when fibrous adhesions have formed between the various organs, and reduction has become difficult, caution must be observed. Surgical treatment is always a serious matter, and should only be attempted in the case of valuable breeding animals, or those which cannot be sold for slaughter.
Young animals are kept without food for twenty-four hours and are cast on the side opposite the hernia; they can be placed on the right or left side, or on the back, as seems most convenient. The site of operation is disinfected, and the operation carried out with aseptic precautions. The skin covering the swelling is incised and, the margins of the hernial orifice having been examined, the sac is isolated. Next, an incision is carefully made, any adhesions which may exist are broken down and the herniated parts are reduced. It only remains to suture the wound with silk or catgut, bringing the lips of the fissure together. Finally the skin wound is firmly united, and a large suspensory bandage tightly applied.
If the hernia is of long standing, and is irreducible on account of numerous adhesions, operation may still be attempted. In that case the incision must be an inch or two longer, all adhesions should be destroyed, and the margins of the orifice need to be freshened so as to insure their uniting.
During the days following operation, the animals should have light food, principally gruel, mashes and cooked roots. But it must be borne in mind that this operation is serious, and may possibly be followed by eventration.
DIAPHRAGMATIC HERNIA.
The term diaphragmatic or mediastinal hernia denotes a condition in which certain of the abdominal viscera penetrate into the thoracic cavity. This displacement may be congenital, acquired, or accidental.
The accidental herniæ are of traumatic origin, and are often caused by fractured ribs, which injure the diaphragm. The hernia is then purely diaphragmatic.
Congenital or acquired herniæ are more frequently mediastinal; they occur exactly in the median plane as a consequence of fissure of the diaphragm above the ensiform cartilage, and cause a separation between the two layers of serous membrane enclosing the posterior mediastinum.
The region immediately behind the diaphragm in the ox being occupied by the large viscera—namely, the anterior conical portions of the rumen, the reticulum, the omasum, and the liver—diaphragmatic or mediastinal hernia is far from being common, though occasionally it may be discovered or at least suspected.
Causation. The causes of diaphragmatic and mediastinal hernia are closely connected with injuries in the region of the hypochondrium; with arrest in the development of the diaphragm; or with accidental vertical fissuring consequent on gestation or acute tympanites.
The fissure seems most commonly to occur between the point where the œsophagus passes through the diaphragm and the ensiform cartilage of the sternum, in which case mediastinal herniæ most commonly supervene. As, on the other hand, the rumen, owing to its size, form and position, cannot readily be displaced, the reticulum and omasum are the viscera which most commonly pass into the thorax.
Symptoms. In true accidental diaphragmatic hernia visceral displacement only occurs on the right side, and symptoms of this are immediately apparent. The passage of the liver, reticulum, or omasum into the right pleural sac compresses the lung, causes attacks of dyspnœa and acceleration of the heart’s action.
Fig. 223.—Intra-mediastinal diaphragmatic hernia (viewed in position from the left side). P, Lung; C, heart (displaced); D, diaphragm; H, hernial mass.
Percussion may not reveal any important change, but on auscultation digestive sounds can plainly be heard within the chest.
The symptoms are far from being well defined. They may be more or less intense, and colic may or may not be present. Mediastinal hernia (Fig. 223) appears to develop slowly, and it is only by degrees that the viscera become displaced.
There is then no sudden change, no clearly marked disturbance, but simply a certain amount of digestive irregularity, together with loss of appetite, cessation of rumination, slight indigestion, and moderate tympanites. The disturbance is really due to obstruction in the alimentary canal and displacement of the reticulum and omasum, so that rumination and deglutition are affected.
Very often this condition may last for weeks, in either a stationary or more or less aggravated form, so that there is an appearance of chronic gastro-enteritis, motor dyspepsia, or chronic indigestion.
Though a diagnosis in this sense would be correct, the atony of the rumen is not primary, but of mechanical origin.
One indication is constantly present, which might suggest indigestion due to overloading of the rumen, and which is also seen in ulcerative gastritis, viz., progressive stasis of food in the cavity of the rumen. When the patients remain for some time under observation, this stasis becomes every day more marked, and, being recognised, the diagnosis becomes easier. Animals suffering from mediastinal hernia lose condition, waste away, and in the end may die in a state of cachexia.
Fig. 224.—Schema of the position of the organs in the hernia represented by Fig. 223. D, Diaphragm; FF1, liver; Pl, pleura; Fe, omasum; Re, reticulum; CC, abomasum.
Lesions. The lesions vary greatly. In accidental diaphragmatic hernia they are confined to rupture of the diaphragm, sometimes of the liver, and to changes in the reticulum or omasum.
In intra-mediastinal hernia the layers of the mediastinum form a true hernial sac, and if the lesion is of old standing the displaced viscera may become attached to it, compressed, and partially strangulated.
Diagnosis. The diagnosis is very difficult, at all events in mediastinal hernia, and can only be arrived at by a process of exclusion. The most significant symptom is progressive stasis of food within the rumen, suggestive of some obstacle in the alimentary canal.
Prognosis. The prognosis is extremely grave, because it is impossible to reduce the hernia.
Treatment. No treatment is possible. The essential point is to confirm the diagnosis as soon as possible and to slaughter the animal while it is yet in good condition.
EVENTRATION.
Eventration belongs to the same group of lesions as herniæ, of which it is merely a more serious form. It differs from them only in the fact that the entire abdominal wall is injured. The skin, muscle, and peritoneum are torn, and the digestive organs pass into direct communication with the external air.
The name eventration has also been given to enormous subcutaneous abdominal herniæ, in which the sero-muscular wall is injured over a large area and the viscera become displaced and separate the subcutaneous tissue layers while at the same time they alter the whole shape of the abdomen.
Causation. The cause is always the same—some grave mechanical injury to the abdominal wall, producing an extensive perforation. The injury may be due to a horn thrust or to the animal falling on some sharp-edged body.
The symptoms are very marked. Through the wound, the rumen, the abomasum, or the intestine protrudes more or less. Generally it is the small intestine which becomes displaced, because it is the most mobile of the abdominal viscera. These organs soon become dried by contact with the air, and may become infected, soiled, congested, thickened, torn, or gangrenous. The successive development of these changes causes serious and violent colic, accompanied by expulsive efforts; the animals throw themselves on the ground, and may tear the mesentery, the intestines, etc. At an advanced stage the animal may stand motionless, looking at its viscera. Death may also be caused in a very short time by the intense pain.
Diagnosis and Prognosis. The diagnosis is evident. The prognosis is always very grave, although, of course, it depends on the condition of the displaced viscera.
Treatment. It is often useless to attempt anything, and if the animal is in suitable condition it is best, as a rule, to slaughter it.
If the accident is quite recent, and the viscera only slightly injured, surgical treatment may be attempted. With this object, the displaced organs are carefully and thoroughly washed with lukewarm boiled water, or with some unirritating disinfectant, to guard against peritonitis, and are then reduced.
The abdominal wound must afterwards be carefully sutured. This is performed in two stages. The musculo-serous layer is first brought together with catgut, or better still with silk, and the skin joined by means of deep and closely placed stitches. To prevent these sutures being torn out, and to support them, the abdomen is swathed in a broad cloth bandage, tightly applied.
FISTULÆ OF THE DIGESTIVE APPARATUS.
Fistulæ of the digestive apparatus are of accidental origin and of relatively small practical interest. In most cases they necessitate surgical and other treatment of too delicate a kind and too prolonged a character to justify the necessary expense. Their nature and origin sufficiently suggest the course to be adopted.
Fig. 225.—Fistula of the rumen.
These fistulæ are divisible into two varieties, gastric fistulæ and intestinal fistulæ. Gastric fistulæ comprise fistulæ of the rumen, reticulum, and abomasum. They may be of external origin, but in the majority of cases they are produced by foreign objects accidentally swallowed and eliminated through the medium of an abscess of the abdominal walls. Their position and direction indicate their point of origin. (Fistulæ of the rumen appear on the left side of the reticulum, near the ensiform cartilage and middle line; those of the abomasum on the right side, near the middle line.) In doubtful cases, chemical analysis of the liquid which escapes will afford valuable information. Acidity alone is a sufficient indication in fistula of the abomasum.
Fistulæ of the rumen and reticulum are difficult to close on account of their low position in the abdominal wall, but, if great care is exercised, they may be successfully treated. Those of the abomasum, on the contrary, only tend to increase in size, and any surgical interference still further favours the destructive action of the gastric juice. As a rule, therefore, they cannot be treated.
Fistulæ of the second variety comprise all intestinal fistulæ. They may be either accidental or artificial, and they are less grave than gastric fistulæ, because they are rarely situated in the lower portions of the abdomen. With time they may become closed either spontaneously or by means of simple treatment tending to regulate the passage of food through the bowel.