IMPACTION OF THE OMASUM (THIRD STOMACH).
Definition. Synonyms. Causes, torpid action, defective insalivation, inactive rumen, fever, inflammation, spinal paresis, dry, fibrous, innutritious food, fungi, ergot, smut, privation of water, or of succulent food, microbian ferments and their products, chronic heart disease, dry farinas, extreme changes of diet, brain disease. Symptoms: slight or violent; ill health, impaired appetite and rumination, grunting, tympany, diarrhœa, constipation, baked coated fæces, percussion signs, separation from herd, red eyes, stiffness, agalactia, fœtid eructations, paralysis, drowsiness, stupor, delirium, nervous symptoms mostly in acute cases. Course in chronic and acute cases. Diagnosis; from pneumonia, and overloaded rumen. Lesions; solid impacted omasum, baked contents, shedding of epithelium, congestion, petechiæ, ulceration, empty, and congested abomasum and small intestine. Treatment: laxative food, purgatives, stimulants, antiseptics, enemata, stimulants of peristalsis, counter-irritants, mucilages, laxative diet, tonics.
Definition. This may be defined as a form of indigestion of which the prominent feature is the drying and impaction of the ingesta between the folds of the third stomach. It may seem to be a primary disease, but in very many cases it occurs as a result of some acute febrile or inflammatory affection.
Synonyms. As the disease has been long popularly known it has received a variety of popular names which are more or less characteristic. Dry murrain, Clewbound, Fardelbound, Stomach staggers, Grass staggers, Vertigo, Chronic dyspepsia, and Chronic indigestion may serve to illustrate these.
Causes. Torpor of the manifolds and the suppression of secretion of saliva, together with the absence of a continuous access of waves of liquid floating the finely divided food from the mouth or rumen to the third stomach are prime conditions of dessication of the contents. The third stomach, like the two first, has no provision for liquid secretion, but is dependent for its supply on constant flushing from in front. If therefore feeding and rumination are interrupted as the result of a febrile disease, if the secretion of saliva is in great part suppressed, if the vermicular movements of the rumen and resulting overflow into the third stomach are checked, and if in addition the omasum itself is rendered torpid, the ingesta compressed between its folds becomes drained of its liquid, and in no great length of time, to such an extent that it may be rubbed up into a dry powder. All this is a necessary result of an acute febrile condition, and therefore all febrile and inflammatory affections tend to drying and impaction of the contents of the omasum. If therefore the observer were to go no further than this he would have a very simple pathology, for all or nearly all fevers and inflammations would be to him simply impacted omasum. In the great majority of cases this condition is to be looked on as a secondary and subsidiary affection, while the real primary disease has still to be sought for.
Some explanation of the special susceptibility of the third stomach in such constitutional troubles, is found in the source of innervation of the viscus. Colin and Ellenberger could rouse the movements of the first two stomachs but not of the third by electric stimulation of the vagus, while the third stomach was excited to action by excitation of the spinal cord and of the sympathetic twigs proceeding from this to the manifolds. Ellenberger indeed avers that the walls of this viscus are abundantly furnished with ganglionic cells which are called into action by this sympathetic stimulus. The innervation being derived from an independent source, derangement of the third stomach may be quite independent of any primary disorder of the first, and the omasum deriving its motor supply from sources so closely related to the vaso-motor ones, may give an additional explanation of the intimate connection of its disorders with febrile and inflammatory diseases.
But while acknowledging the controlling influence of torpor or paresis of the omasum, it would be an error to follow Cadeac in denying the influence of food as a cause of impaction. It has long been notorious that impaction of the omasum is preëminently a disease of winter, or of the period of dry feeding. It occurs in cattle fed on dry, fibrous, innutritious fodder, and especially when there is a scarcity of water, or when in connection with severe frost the usual water supply has been frozen up. It prevails in stock turned in spring or autumn on pastures in which the fresh green grass grows up among the dead, dried and withered stems of a previous growth and tempts them to eat them. It appears when the stock consumes corn or cornstalks affected with smut or certain other fungi, or the cereals or grasses suffering from ergot or smut, but this is especially the case when there is also a privation of water, whereas, with an abundant water supply or a partial ration of roots, potatoes or ensilage the danger is greatly reduced. Sometimes a change from soft to very hard water appears to act as a cause but whether from a special astringent action or a disinclination to consume the usual amount has not been made clear.
It must be allowed that the sheep and goat which habitually drink little, suffer far less from this affection than the ox which drinks freely, yet allowance must be made for the constitution and long settled habits of the genus, and we must not forget that it is usually under privation of water or a restricted supply that the ox suffers.
Among other causes must be named fermented food, the microbian ferments and their products, serving to render the organ torpid, but also to produce fever, lessened secretion and an arrest or retardation of liquid supplies from the mouth or rumen.
Chronic heart disease, causing blood stasis in the omasum, appears to induce torpor and favor impaction.
The ingestion of lead has a very direct action in producing paralysis and consequent impaction.
Finally, finely divided dry food like meal or bran, swallowed hastily, tends to pass in large amount directly into the omasum, and, before the animal has become accustomed to the ration, is liable to clog the viscus and induce impaction.
In nearly all cases, the commencing impaction entails a certain rise of temperature and suppression of secretions, so that the malady tends to move in a vicious circle, each new step tending to aggravate the already existing condition. In chronic cases, which are very common, a careful record of bodily temperature shows oscillations, above and to the normal, at irregular intervals, each rise tending to add to the impaction.
The most acute and fatal forms of the affection occur in connection with a sudden change from dry to rich, luscious, green food in spring, the unwonted stimulus giving rise to general irritation of the whole gastric mucosa, with disordered and impaired function of all four stomachs, but especially of the third. Such cases are usually congestive and inflammatory and the suspension of the gastric movements is a grand cause of impaction. In such cases too the brain or spinal cord, or both, are seriously involved, and the early death is preceded by torpor, paralysis, violent delirium or convulsions, following largely the type of acute lead poisoning.
Symptoms. These vary according to the degree of impaction or gastric torpor, from simple, irregular, or suspended rumination (loss of cud) to the most severe gastric and nervous disorder.
The slighter or less acute cases are marked by a failure to re-establish regular rumination on partial convalescence from a fever or inflammation. The hyperthermia subsides, but the appetite remains poor and capricious, the muzzle dry, the eyes dull, the spirits low, breathing quickened and occasionally accompanied by a moan, especially when moving down hill, slight tympanies of the rumen may appear and the contents of that organ seem consolidated and may be felt as solid masses when pressure is made by the hand. The mouth is hot, clammy and fœtid, and the bowels costive, the fæces being passed in small amount and in the form of hard, black pellets, covered by a film of mucus, or streaks of blood, and containing particles of undigested food. This not unfrequently merges into a transient diarrhœa to be followed in turn by renewed constipation, and such alternations may repeat themselves again and again. The omasum is so deeply seated under the ribs on the right side that exploration is unsatisfactory, especially in the milder cases, yet pressure of the closed fist upward and forward below the middle of the chest will give the impression of a specially solid resistance and the patient may indicate suffering by a moan. Percussion with the closed fist has the same effect. There may be slight tremors of the body, the horns, ears and limbs are cold, and the hair erect in patches, dry and lustreless.
In cases occurring independently of previous disease, diarrhœa may be the first symptom noted, the malady being preceded by local irritation and congestion, but this soon gives place to constipation with alternating diarrhœa and the general train of symptoms above mentioned. The animal leaves the herd and is found lying apart on its left side with the nose in the right flank, the pulse and breathing quickened, the eyes congested, and a moan emitted occasionally in expiration. This is increased if the patient is raised and driven, especially down hill. He walks with stiff, arched back, unsteady gait and dragging limbs. Appetite may not be entirely lost at first, but only impaired and irregular, and as rumination ceases, grinding of the teeth becomes common. The secretion of milk is diminished or altogether arrested, and emaciation advances day by day. Fœtor of the eructations, the result of prolonged and septic fermentation in the rumen, is often a marked symptom.
This form may last from ten to fourteen days and merge finally into paralysis of the hind limbs, drowsiness and stupor, or delirium and convulsions.
In the more acute cases resulting from a sudden access of green food, a change of water, or the ingestion of irritant plants, the affection partakes more or less of the nature of congestion or inflammation of the viscus, and may run a rapidly fatal course. The animal may be seen apart from the herd in the characteristic recumbent position, with eyes red and glassy, eyelids semi-closed, and much drowsiness and stupor, but when raised he may still feed in a sleepy, listless manner. The bowels may be loose or confined, the pulse and breathing accelerated, the right hypochondrium firm and tender, and as in the other forms the crepitating sound of fermentation is slight or absent over the region of the manifolds. Soon nervous disorder appears, the eyes glare wildly, the animal seeks relief in motion, it may be in a straight line, or to one side, and being blind and unconscious of obstacles he may fall into pits, or ditches, dash against trees, fences or buildings, and if they offer sufficient resistance he will continue pushing, breaking teeth or horns, and subject to violent muscular contractions, causing even the grubs to start from the back. The nervous disorder is often further shown in loud and terrified bellowing as if chased by a dog or gored by one of its fellows.
Course. Chronic cases may continue almost indefinitely the victims showing merely poor health, impaired digestion, and steady loss of condition. After death the omasum is sometimes found to contain dried materials, such as the animal has not had access to for from three to five months.
In those which end in an early recovery there occurs a free and abundant diarrhœa, the fæces containing solid flattened masses with black baked or polished surface, the result of the detachment of the impacted layers from between the folds of the third stomach. The tympany of the rumen subsides, crepitation is renewed in the rumen and omasum, there is free rumbling in the bowels, and the appetite gradually improves. The softening and removal of the dessicated contents are slow and it may be weeks before there is a complete restoration to normal conditions.
Diagnosis. The hurried pulse and breathing and the grunting with expiration may be mistaken for pneumonia or pleurisy, but the distinction can be made as in impacted rumen. There is at first no fever, the tenderness is confined to the right side, the percussion dullness of the chest is in the posterior part and distinctly referrible to the loaded abdominal viscera, it is attended by no pulmonary crepitation, indeed crepitation in rumen and omasum is lessened or abolished, there is no pleural effusion, but there are the unquestionable signs of gastric and intestinal disorder.
It may be confounded with overloading of the rumen, but in the latter case the distension occurs rapidly, there is little or no indication of movement of the viscus, appetite and rumination are usually early suspended and the gaseous eructations are not putrid.
Postmortem Appearances. These are essentially connected with the impaction of the omasum. This organ is gorged to twice its normal size or larger, firm, solid and resistant, not easily taking an impression of the finger, and having at times an almost stony hardness. When incised the intervals between the folds are sure to be packed with dessicated food, often so dry in the upper part that it may be rubbed down into a grayish powder, and it has been compared to the cakes of linseed as they come from the press. The surface of such cakes is smooth and dark, and usually covered by a layer of epithelium which has detached itself from the surface of the fold. This is usually quoted as a morbid desquamation, but inasmuch as we frequently see it in perfectly healthy conditions in animals killed in abattoirs, it must be admitted to occur also as a normal physiological exfoliation. The exposed mucosa shows spots and patches of congestion, extravasation, and even at times ulceration, or slight areas of necrosis.
The rumen shows the result of torpor and inactivity. The ingesta is largely packed into solid masses, which have advanced from the simple acid fermentation, to evident putrefaction with offensive emanations. The abomasum is empty or nearly so of ingesta, but contains abundance of mucus and shows patches of congestion as in prolonged abstinence.
The small intestine is also empty and collapsed, with considerable redness and congestion. The larger intestine contains a small quantity of feculent matter, dry, massed in small pellets and with smooth glistening surface. Mucus is abundant and dense.
Treatment. This must follow the same lines as in impaction of the rumen with the understanding that the response is less certain and the result somewhat more tardy in reaching complete convalescence. In mild and chronic cases a liberal allowance of flaxseed tea, several bucketfuls per day, will often succeed.
In using purgatives those are usually the best which lead to drinking abundantly. For the ox a pound each of Epsom and common table salt, with an antiseptic stimulant like aqua ammonia (3 to 4 drachms) or oil of turpentine (2 oz.) will often act favorably. The sodium chloride is antiseptic, and induces ardent thirst and if there is free access to water, tepid or not too cold, purgation is early secured and the impacted cakes in the manifolds are slowly softened, detached and removed. But unless water is given freely the salt will prove irritating and even injurious.
In obstinate cases, and in the absence of indications of gastric or cerebral congestion the addition of 20 croton beans or 20 drops of croton oil will be excellent. Nux vomica (½ drachm) is also of value in rousing the torpid nervous action. Injections are always in order, and it is recommended to use these cold so as to rouse the muscular action of the intestine and stomach.
Some of the newer remedies which rouse the contractility of the digestive organs and at the same time stimulate secretion serve an excellent purpose in these cases. Eserine 1½ grain, veratrine 1 grain, barium chloride 10 to 15 grains, or pilocarpin 3 grains may be given hypodermically in addition to the usual purgative. The pilocarpin is theoretically the best as its tendency is to cause free secretion from all mucous surfaces, and even a slight secretion from the omasal folds will greatly favor detachment and discharge of the impacted plates. These as well as the stimulants may be repeated as the effects pass off. The purgatives on the other hand should be given at first in a large dose, and not repeated except under the stress of necessity as their constant repetition in small doses seems to nauseate the animal and even to retard action. In the case of profuse secretion from the kidneys however it may be supposed that the saline agents have passed off in that way and a purgative may be safely repeated. It may be well however to use one which is less likely to stimulate the kidney, such as castor, olive, or raw linseed oil or senna.
The patient may be several days or even a week without alvine discharge and yet do well. If there are fever and other indications of gastric congestion a blister to the right hypochondrium may be of value. Rub well with oil of turpentine and then with a pulp of the best ground mustard and tepid or cold water and cover with sheets of thick paper to prevent evaporation.
If nervous, symptoms are manifested by dilated pupils, blindness, congested conjunctiva, hot horns and ears, and drowsiness, or excitability apply cold water or an icebag to the head and continue as long as may be needful. If the patient should become violently delirious he may be fastened to a beam overhead in the centre of the stall so as to prevent him from injuring himself or others.
In these cases the more violent and irritant purgatives are to be avoided, and decoctions of slippery elm, linseed or gum may be given to sheathe and protect the irritated membrane.
Even though a free action of the bowels has been secured it is not to be assumed that all impacted material has been removed. A specially laxative diet of roots, ensilage, or succulent green food, with a liberal supply of salt, and free access to water should be kept up for some weeks to secure a complete softening and expulsion of the impacted material. Repeated small doses of laxative medicine may be requisite to bring this about. As a rule a course of tonics, and above all of nux vomica is valuable in re-establishing the normal tone of the stomachs and intestines.