Diyala University
Stage : 4th Stage
Faculty of Veterinary Medicine
Subject: Internal Medicine
By: Dr. TAREQ RIFAAHT MINNAT (No.4)
Diseases of the liver
 Introduction
The liver has many functions, these functions are: The detoxification and excretion of many toxic substances,
including photodynamic agents (drugs or toxins) of the blood
stream.
 The maintenance of normal blood glucose levels by providing the
source as glycogen (regulation of blood-sugar levels).
 maintenance of blood protein and cholesterol levels.
 The formation and excretion of bile salts (that helps to metabolize
fats) and the excretion of bile pigments.
 The formation of prothrombin.
 Production and maintenance of normal blood-clotting factors.
The basic disease processes are divided into: Infection
 Inflammation
 Toxicity
 Cancer
 Metabolic disease
 Congenital diseases
 Trauma.
Most people think hepatitis (inflammation of the liver) is a viral
disease, because this is common in people. But viral hepatitis is
very uncommon in dogs. Cats can develop hepatitis as part of the
viral disease feline infectious peritonitis.
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Diyala University
Stage : 4th Stage
Faculty of Veterinary Medicine
Subject: Internal Medicine
By: Dr. TAREQ RIFAAHT MINNAT (No.4)
 Principle of hepatic dysfunction
Diffuse and focal hepatic diseases
Diffuse diseases of the liver are more commonly accompanied by signs of
insufficiency than are focal diseases, which produce their effect either by
the toxins formed in the lesions or by pressure on other organs, including
the biliary system. The origin of a toxemia is often difficult to localize to
the liver because of the physical difficulty of examining the organ.
Diffuse diseases of the liver can be classified as hepatitis and hepatosis
according to the pathological change that occurs and type of causative
agent. Clinically the differences between these two diseases are not
marked, although some assistance can be obtained from
clinicopathological examination.
Hepatic dysfunction
There are no specific modes of hepatic dysfunction. The liver has
several important functions and any diffuse disease of the organ interferes
with most or all of the functions to the same degree. Variations occur in
the acuteness and severity of the damage but the effects are the same and
the clinical manifestations vary in degree only.
Portal Circulation
The portal circulation and the liver are mutually interdependent, the liver
depending upon the portal vein for its supply of nutrients and the portal
flow depending upon the patency of the hepatic sinusoids. The portal
flow is unusual in that blood from the gastrosplenic area and the lower
part of the large intestine passes to the left half of the liver and the blood
from the two intestines to the right half, without mixing of the two
streams in the portal vein. The localization of toxipathic hepatitis may be
because of selective distribution of the toxin or of protective metabolites.
The passage of blood from the portal circuit through the liver to the
caudal vena cava is dependent upon the patency of the hepatic vascular
bed, and obstruction results in damming back of blood in the portal
system, portal hypertension, interference with digestion and absorption,
and in the final stages the development of ascites.
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