Amphistomum Conicum. This is a trematode worm about the size of an apple-seed (10 millimetres long by 2 millimetres thick), rounded at both ends, slightly curved on itself, and, as usually found, of a bright red color. It attaches itself by its sucker (on thick end), usually in the vicinity of the demicanal. Its life history is closely allied to that of the distomata, but as it is not known to prove at all injurious to its host, it possesses no pathological importance.
Actinomycosis of the Rumen and Reticulum. Tumors of this fungus are sometimes found in the walls of the two first stomachs projecting in the form of polypi, or imbedded in the thickness of the coats. Where they are completely covered by the mucous or serous membrane their true nature is not readily recognized. When incised they show the characteristic yellow granules made up of club-shaped cells, though the usual stellate arrangement may be somewhat imperfect. From the serous surface the growth may invade the different adjacent organs. It is impossible to diagnose a primary actinomycosis of the rumen, if unaccompanied by more superficial lesions, but, if the disease is recognized elsewhere, the same general treatment with iodide of potassium will dispose of these formations as well.
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.