In man cirrhosis is looked upon as almost always the result of abuse of alcohol. In animals this cannot be the case, apart from a few kept in connection with breweries or distilleries.
In heart disease a long continued mechanical congestion of the liver causes compression and degeneration of the secreting cells in the centre of the acini (around the intralobular veins), while the peripheral portions undergo cell proliferation and increase of connective tissue.
In chronic or recurrent perihepatitis, a whole lobe may be compressed by the hyperplasia of the investing connective tissue, and the hepatic cells are degenerated and absorbed.
Overdistension of the biliary ducts from obstruction to the flow of bile (gall stone, catarrhal inflammation, constipation), leads to proliferation and hyperplasia in the walls of the biliary radicals throughout the entire liver.
The presence in the liver of toxic agents, ingested, or generated from microbian fermentation in the intestinal canal or liver is another recognized cause of connective tissue hyperplasia.
CIRRHOSIS IN THE HORSE.
Cirrhosis of venous origin has been observed mainly in old horses, while hypertrophic cirrhosis from biliary obstruction occurs rather in the young (Cadeac). Bruckmüller records a case of the first kind in a horse with extreme pulmonary emphysema. Walley gives a bad condition of fodders as the main cause, virtually implying, in many cases, infective catarrh and obstruction of the biliary ducts.
A form of the disease prevails at Schweinsberg in Hesse, and has been variously attributed to spoiled fodders (Nicklas), to vegetable alkaloids and other poisons in the food (Friedberger and Fröhner), to clover, to telluric poisons (Redner), to infection (Meminger), and to heredity (Neidhardt). It is a suggestive fact that it is confined to the valleys of the Ohm, Glon, and Zusam where the land is peaty or swampy and subject to inundations, while it is unknown on the dry table lands (Friedberger and Fröhner). This strongly suggests intoxication with microbes or their deleterious products. The gastric catarrh that frequently attends the disease may point in the same direction.
Symptoms. These are too often general rather than diagnostic. Dullness, prostration, hebetude, yawning, hot, sticky mouth, lost, irregular or depraved appetite, colics, constipation or diarrhœa, dry, harsh coat, emaciation, weakness, œdema of the limbs, vertigo and drowsiness may be among the symptoms. More characteristic are icterus, abdominal distension from ascites, or congestion of the liver, yellow or high colored urine, intestinal catarrh, indigestion, and tenderness in the region of the liver. The mucosæ are usually pale at first and not always icteric later. On exertion the horse shows early fatigue, tumultuous heart beats and oppressed breathing.
The Schweinsberg disease often lasts for months, with alternate improvements and exacerbations, but almost invariably ends in death, and sometimes completely depopulates a stable.