Part 91

Symptoms. In such a case the only definite symptoms are those of internal hemorrhage, pallor of the mucous membranes, gradually increasing weakness, vertigo, unsteady gait, and an early death. In more protracted cases slight jaundice, dullness, prostration, stupor, drooping of head, ears and eyelids, resting it on the manger or walls, muscular weakness, crossing of the front limbs, and it may be tenderness on percussion on the right side of the chest posteriorly. It resembles the coma or immobility of the horse but the patient backs more easily.

Cattle. In ruminants sharp pointed bodies passing from the rumen will occasionally penetrate the liver, and give rise to symptoms of hepatic disorder. Augenheister found in a cow dilatation of the larger bile ducts, which contained about 10 quarts of sand, that had apparently entered from the duodenum by the common bile duct which had an orifice of an inch in diameter.

Pig. The gall ducts of a pig’s liver, in the Veterinary College of Berlin contains a large amount of sand (Gurlt).

Dog. The liver is exceptionally perforated by sharp pointed bodies coming from the stomach. Cadeac and Blanc report three cases of needle in the liver. Blanc’s case had been killed because of old age; one of Cadeac’s showed symptoms resembling rabies.

Treatment of these cases would be very hopeless as nothing short of laparotomy and the removal of the foreign body would promise success.

TUMORS OF THE LIVER. NEW GROWTH.

Largely secondary, from stomach, intestine, lymph glands, spleen, pancreas; the hepatic tumor may be disproportionately large. In horse: sarcoma rapidly growing soft, succulent, slow-growing, fibrous, tough, stroma with round or spindle shaped cells and nuclei. Symptoms: emaciation, icterus, enlarged liver, rounded tumors on rectal examination. Melanoma, in old gray or white horses, with similar formations elsewhere; not always malignant. Lymphadenoma. Angioma. Carcinoma. Epithelioma, lesions, nodular masses, white or grayish on section, and having firm stroma with alveoli filled with varied cells with refrangent, deeply staining, large, multiple nuclei, cancerous cachexia and variable hepatic disorder. In cattle: sarcoma, adenoma, angioma, cystoma, carcinoma, epithelioma. In sheep: adenoma, carcinoma. In dog: lipoma, sarcoma, encephaloid, carcinoma, epithelioma. Wasting and emaciation, yellowish pallor, temporal atrophy, ascites, liver enlargement, tender right hypochondrium, dyspepsia, symptoms of primary deposits elsewhere.

The great quantity of blood which passes through the liver lays it open, in a very decided way, to the implantation of germs and biological morbid products. Hence tumors of the liver are largely secondary, the primary ones being found mostly in the stomach, intestine, abdominal lymph glands, spleen and pancreas. The primary neoplasm is often comparatively small, while the hepatic one supplied with a great excess of blood may be by far the most striking morbid lesion. The hepatic tumors are mostly of the nature of angioma, sarcoma, melanoma, adenoma, lipoma, cystoma, carcinoma, and epithelioma.

NEOPLASMS IN HORSES LIVER.

Sarcoma. This is usually a secondary formation from the primary tumors in the spleen and peritoneum, and it occurs as multiple masses throughout the substance of the gland. The liver is greatly increased in size, extending far beyond the last rib on the right side, and weighing when removed as high as 70 ℔s. (Mason), or even 88 ℔s. (Cadeac), in extreme cases.

The whole surface of the liver may show bulging, rounded masses, and the morbid growth may have involved the capsule and caused adhesion to the back of the diaphragm (Bächstädt). The cut surface of the neoplasm is smooth, elastic, yellowish and circular or oval in outline. It may have a variable consistency—friable or tough, according to the activity of growth and the relative abundance of cells and stroma. The portal glands are hypertrophied and thrombosis of the portal vein is not uncommon.

Microscopic examination of the dark red scrapings shows numerous blood globules, intermixed with the round or spindle shaped cells and nuclei of the tumor. Sections of the tumor show these cells surrounded by a comparatively sparse fibrillated stroma. The round cells may vary from .005 to .05 m.m. They contain one or more rather large nuclei and a number of refrangent nucleoli. The nuclei are often set free by the bursting of the cells in the scrapings. They become much more clearly defined when treated with a weak solution of acetic acid. Small grayish areas in the mass of the tumor represent the original structure of the liver, the cells of which have become swollen and fatty.

A liquid effusion more or less deeply tinged with red is usually found in the abdominal cavity.

Symptoms are those of a wasting disease, with some icterus, sometimes digestive disorder, and a marked enlargement of the liver. The last feature can be easily diagnosed by palpation and percussion. If an examination through the rectum detects the enlargement and irregular rounded swellings of the surface of the liver or spleen, or the existence of rounded tumors in the mesentery or sublumbar region, this will be corroborative. The precise nature of the neoplasms can only be ascertained after death.

Melanoma. Melanosis of the liver is comparatively frequent, especially in gray horses, and above all when they are aging and passing from dark gray to white. In many cases a more certain diagnosis can be made than in sarcoma for the reason that primary melanotic neoplasms are especially likely to occur on or near the naturally dark portions of the skin, as beneath the tail, around the anus or vulva, in the perineum, sheath, eyelids, axilla, etc. The extent of the disease is likely to be striking, the liver, next to the spleen, being the greatest internal centre for melanosis. The whole organ may be infiltrated so that in the end its outer surface is completely hidden by melanotic deposit. The surface deposits tend to project in more or less rounded, smooth masses of varying size according to the age of the deposit and the rapidity of its growth. Individual deposits may vary in size from a pea to a mass of 40 or 50 lbs. They are moderately firm, and resistant, and maintain a globular or ovoid outline. The color of the melanotic deposits is a deep black with a violet or bluish tint. If the pigmentary deposit is in its early stage it may be of a dark gray. The deposits are firmer than the intervening liver tissue and rarely soften or suppurate.

Melanosis in the horse is not always the malignant disease that it shows itself to be in man, and extensive deposits may take place externally and considerable formations in the liver and other internal organs without serious impairment of the general health. It is only in very advanced conditions of melanosis of the liver that appreciable hepatic disorder is observed. If, however, there is marked enlargement of the liver, in a white or gray horse, which shows melanotic tumors on the surface, hepatic melanosis may be inferred.

Lymphadenoma. Adenoid Tumor. Lienaux describes cases of this kind in which the liver was mottled by white points which presented the microscopical character of adenoid tissue, cells enclosing a follicle and a rich investing network of capillaries.

Angioma. These are rare in the horse’s liver, but have been described by Blanc and Trasbot as multiple, spongy tumors on the anterior of the middle lobe, and to a less extent in the right and left, of a blackish brown color, soft and fluctuating. The largest mass was the size of an apple, and on section they were found to be composed of vascular or erectile tissue. The tendency is to rupture and extensive extravasation of blood (30 to 40 lbs.) into the peritoneum.

Carcinoma. Epithelioma. These forms of malignant disease are not uncommon in the liver as secondary deposits, the primary lesions being found in the spleen, stomach, intestine, or pancreas, or more distant still, in the lungs. The grafting or colonization of the cancer in the liver depends on the transmission of its elements through the vena portæ in the one case, and through the pulmonary veins, the left heart and hepatic artery in the other.

Lesions. The liver may be greatly enlarged, weighing twenty-seven pounds (Benjamin) to forty-three pounds (Chauveau), hard, firm, and studded with firm nodules of varying sizes. These stand out from the surface, giving an irregular nodular appearance, and are scattered through its substance where, on section, they appear as gray or white fibrous, resistant, spheroidal masses shading off to a reddish tinge in their outer layers. Microscopically these consist of a more or less abundant fibrous stroma, enclosing, communicating alveoli filled with cells of various shapes and sizes, with large nuclei (often multiple) which stain deeply in pigments. The relative amount of fibrous stroma and cells determines the consistency of the mass, and whether it approximates to the hard cancer or the soft. In the horse’s liver they are usually hard, and, on scraping off the cut surface, yield only a limited quantity of cancer juice. In the epithelial form, which embraces nearly all that have originated from primary malignant growth in the walls of the intestine, the epithelioid cells, flattened, cubical, polyhedral, etc., are arranged in spheroidal masses or cylindrical extensions, which infiltrate the tissues more or less. These seem in some cases to commence in the radical bile ducts (Martin), and in others in the minor coats of the larger biliary ducts.

As the disease advances a brownish liquid effusion is found in the abdomen, and nodular masses formed on the surface of the peritoneum.

Symptoms. As in other tumors of the liver these are obscure. As the disease advances there may be œdema of the legs and sheath, indications of ascites, stiff movements, icterus, occasional colics, tympanies, and diarrhœa. Nervous symptoms may also appear, such as dullness, stupor, coma, vertigo and spasms. Emaciation goes on rapidly and death soon supervenes.

TUMORS OF THE LIVER IN CATTLE.

Sarcoma. Round or spindle shaped celled sarcomata have been described by Sodero and Cadeac, leading in one case to perforation of the vena portæ and death by hæmorrhage into the peritoneum.

Adenoma. Martin records a case of a hepatic tumor formed of adenoid tissue which had extended into the vena portæ, and microscopically presented a cylindroid character. In the advanced stages it caused some jaundice, digestive disorder, obstinate constipation, progressive and extreme emaciation, and weakness which kept the animal constantly in a recumbent position.

Angioma. These are rarely seen in the young but are comparatively common in old cows as they are in aged men. They form masses of a dark red color and very variable size, and have a limiting sac of connective tissue or merge into the adjacent hepatic structure. Microscopically they consist of a series of irregular lacunæ filled with liquid blood, blood clots, or leucocytes, and communicating with small blood vessels in the walls and partitions. They are believed to be formed by dilatation of the liver capillaries with subsequent thickening of their distended walls, and atrophy of the nearest liver cells. Cases of the kind have been recorded by Kitt, Martin, McFadyean, Saake, Van der Sluys, Korevaar and others. Though often seen in abattoirs, they seem to have little effect on the general health, and no special symptoms have been noted as indicating their existence.

Congenital Cysts. These are found on the anterior surface or lower border of the liver in young calves. They have no connection with the blood vessels, nor biliary canals, contain no head of larval tænia, and do not constantly show the presence of any particular bacterium. These walls are thin and their contents alkaline, with sometimes slight blood extravasation, or a yellowish deposit in which cocci have been found. Unless connected with cirrhosis or other serious disease of the hepatic tissue, their presence seems to have no pathological significance.

Carcinoma. This has been recorded in the liver of cattle by Gurlt, Brückmüller, Kitt and others. From the walls of the gall bladder it grows in pyriform masses, and on the surface and in the interior of the liver, it may appear as hard, cancerous masses of all sizes.