Causes: Mechanical injuries, falls, blows, kicks, degenerations, amyloid, fatty, granular, congestion, neoplasms, glanders, tuberculous, myomatous, microbian infection. In the horse, disease of liver, heart, lungs, hepatic artery, portal vein, degenerations following overfeeding, idleness, foreign bodies, arsenic, phosphorus, parasites, violent movements in colic, running, draught, leaping. In the dog, pampering and traumatism. In cattle forced feeding, emaciation, microbian infection. In birds, tubercle, tæniasis, microbian infection. Lesions: extravasation, intracapsular, or through capsule into the peritoneal cavity. The extravasation bulges of a deep black, covering a dark softened, pulpy, hepatic tissue, with light colored fatty tissue around. Clots may be stratified from successive bleedings. Liver usually enlarged. Symptoms: onset sudden, or preceded by stiffness, soreness and other signs of hepatic trouble. Extensive rupture, entails weakness, unsteady gait, perspiration, pallor of mucosæ, small weak rapid pulse, palpitations, dilated pupils, rolling eyes, amaurosis, tremors, convulsion in case of survival, coldness, œdemas. Death in five hours to five days. Risk of relapse in recovering cases. Treatment: rather hopeless, rest, laxative, ergot, ferric chloride, tannic acid, witch hazel, cold water, snow or ice to right side. In meat producing animals fatten.
Causes. Hemorrhage and rupture of the liver are closely correlated to each other, the accumulation of extravasated blood in the parenchyma in the one case leading to over distension of the capsule, and the laceration of this capsule and of the adjacent substance of the liver occurring in the other as a mere extension of the first. They usually occur as the direct result of mechanical injury (falls, blows, kicks) acting on a liver already softened and friable through disease. These predisposing degenerations may be amyloid (Caparini, Johne, Rabe), fatty (Julien, Gowing, Adam, Siedamgrotzky), granular softening, hepatitis or congestion (Zundel), glander neoplasms (Mathis), tubercles, angiomata (Trasbot), microbian infection (Stubbe), tumors (Brückmüller).
In the horse predisposing conditions may be found in diseases of the liver, heart or lungs, in embolism of the hepatic artery (Wright), in obstruction of the portal vein (Pierre), in infarction of the liver, in degeneration with softening, in sarcomatous, melanotic, glanderous or cancerous deposits in its substance, in degenerations consequent on over feeding, idleness, congestions, on the penetration of husks of grains into the liver substance, on arsenical or phosphorus poisoning. The presence of flukes, echinococci and other parasites may also cause congestion and softening. To the immediate or traumatic causes above named may be added the violent movements attendant on a severe attack of colic, and violent exertions in running, draught, leaping, etc. (Friend).
In the dog we must recognize all the pampering conditions which predispose to congestion and degeneration, together with more direct operation of kicks, blows, falls, fights, over exertion, etc.
In cattle a forcing regimen is especially predisposing, and yet the loss of vigor resulting from a diametrically opposite treatment, must be accepted as an occasional cause. Stubbe found in emaciated cows miliary hemorrhagic infarcts of a dark red color which gradually extended to an inch or more in diameter. These he traced to microbian infection coming by way of the chronic intestinal lesions which are common in old cows. The final result of such infarctions was loss of hepatic substance and the formation of cicatricial tissue with a marked depression on the surface of the organ.
In birds fatal hepatic hemorrhages occur in connection with local tubercle (Cadiot), tæniasis of the liver, or microbian infection.
Lesions. The hemorrhage may take place into the substance of the liver only, or the capsule may be lacerated so that the blood escapes into the peritoneal cavity in considerable quantity.
In the horse it usually occurs in the right or middle lobe, rarely in the left. There may be one or more hemorrhagic effusions varying in size from a cherry to a duck’s egg, or even an infants’ head (Lorge). This projects from the surface of the organ and its deep black contrasts strongly with the white of the adjacent capsule. When laid open the hepatic tissue is seen to be softened and pulpy, and its dark color forms a striking contrast with any surrounding fatty liver. Any form of degeneration may be revealed on microscopic or chemical examination. Not unfrequently small clots of blood form under the capsule raising it in the form of little sacs. Such clots are usually stratified indicating a succession of small hemorrhages.
When the capsule is torn, the lesion may extend from one surface of the organ to the other, and the edges, smooth, uneven or fringed, are united together by a blood clot.
In case of hemorrhagic infarcts the lesion usually has a distinctly conical outline corresponding to the vascular distribution. These are especially characteristic of cases supervening on heart disease.