List of six major diseases of liver found in animals:- 1. Congestion of the Liver 2. Obstructive Jaundice 3. Haemolytic Jaundice 4. Suppurative Hepatitis or Liver Abscess 5. Cholelithiasis or Gall Stone 6. Cirrhosis of Liver.
Contents
Liver: Disease # 1. Congestion of the Liver:
(a) Active Congestion:
That is when an increased amount of blood is brought to the liver by the Hepatic artery.
Active congestion may be brought about when irritating and stimulating materials absorbed from the alimentary tract and specially excessive nitrogenous food such as Brewer’s and Distiller’s grains. It is also conduced to lack of sufficient exercise and is most frequently met in animals that are being overfed and underworked and for show-purpose animals.
Symptoms:
Are very indefinite and may consist of slight additional pain which is most evident after, meals with a slight rise of temperature and general depression. This is followed by the general symptoms of indigestion.
(b) Passive Congestion:
When there is interference with the circulation of the Portal vein and its branches.
Passive congestion of the Portal vein and its branches may be caused by anything which diminishes the flow of blood from the liver on the one hand or anything which diminishes the force of the blood travelling up the Portal vein to the liver. Examples of the former are met with incompetence of the right side of the heart causing regurgitation into the vein, e.g. chronic obstructive lung disease.
Symptoms:
Dullness and depression followed by indigestion, irregular appetite and bowels with a tendency to constipation. The feces very offensive in odour due to insufficient secretion of bile. Mucous membranes are dirty yellowish in colour and the pulse is soft and slow. Vomiting in dogs and cats are frequently met with There is usually some enlargement of the liver.
Treatment:
Horse:
First give a purgative, calomel probably gives the greatest relief. This may be followed on subsequent days with Mag. Sulph.
Cattle and Sheep:
A combination of Mag. Sulph and Sodi. Sulph gives the best results followed by Ammon. Curb, and Nux Vom.
Dogs and Cats:
It is a good plan, first to give an emetic such as Apomorphine Hydrochloride—hypodermically. The act of vomiting exerts mechanical pressure on the liver and may thus reduce the congestion and accelerate the circulation. This should be followed by calomel and subsequently Mag. Sulph and Sodi.
Sulph may be given daily in small doses. When dropsy is present, the abdomen may be tapped, water supply curtailed. Attention must be paid to the diet, which should be somewhat restricted for a day or two and of a laxative and easily digestible character.
(c) Biliary Congestion:
That is when there is interference with the circulation of Portal vein and its branches.
It is a condition, in which tissue and mucous membrane become intensely yellow from staining with bile pigments which is passed into blood stream from the liver. Bile pigments—Bilirubin and Biliverdin are formed from broken down blood cells and have been shown to be produced by the R. E. System i.e. Kupffer cells.
There are three forms of jaundice:
1. Obstructive
2. Haemolytic and
3. Toxic or Infectious.
1. In obstructive jaundice, there is some impediment to the flow of bile into the duodenum. In that condition, the bile pigments are being transferred through the hepatic cells from Kupffer cells to the bile canaliculi and some of it afterwards passed into the blood stream.
2. Haemolytic jaundice is associated with an antecedent of haemglobinemia as in Piroplas- mosis and an excessive amount of bile pigment has been formed in the liver and cannot be transferred to the bile duct and passes into blood stream.
3. Toxic jaundice includes cases in which the hepatic cells are degenerating and are unable adequately to transfer the bile pigment to the bile canaliculi, hence some of the bile pigment passes into blood stream. This is noted in various febrile diseases including Septicaemia and Toxaemia acute inflammation and degeneration of the liver (Phosphorus and Arsenic poisoning). In liver disease, a considerable amount of information towards diagnosis may be got from the examination of urine which may be intensely yellow in colour.
Tests:
Gonchin’s Test:
Pour a little of the suspected urine on a porcelain slab and drop a few drops of Cone. HNO3, if bile pigment is present, a play of colour is seen, green, yellow etc.
Test for bile salts:
Hay’s sulphur Test:
Bile salts decrease surface tension of urine and flowers of sulphur is sprinkled on surface of urine, if bile salts are present even in small quantity, the sulphur particles fall rapidly to the bottom of the vessel.
Test for type of Jaundice:
Vandenberg’s Diazo Reaction:
This test is applied to the blood plasma. A sample of blood is taken, say 15 ml, and to it is added a little Potassium oxalate solution. The plasma is separated after centrifugalisation. To a small quantity of solution, the Diazo’s reagent, i.e. a mixture of Sulphanilic acid, HCI, Sodi. nitrate and water is added.
In some cases, a direct reaction follows and the mixture becomes of a bluish violet colour, viz., Direct reaction. While an indirect reaction is obtained, only after the addition of little alcohol and saturated (NH4)4SO4 solution. The first direct reaction is obtained in obstructive jaundice, while in hemolytic, it is indirect and in toxic, it is delayed.
Liver: Disease # 2. Obstructive Jaundice:
This is a form of jaundice in which there is some impediment to the outflow of bile into or from the duodenum.
Etiology:
It is due to a variety of causes:
(a) Catarrh of the mucous membrane of the duodenum and bile duct causing swelling, narrowing or obstruction of the lumen.
(b) Inspissation of the bile or mucus collected in the bile duct.
(c) Tumours or enlarged glands pressing on the bile ducts.
(d) Gall stones.
(e) Animal parasites, e.g. Ascarides which project into the bile duct from the duodenum, Echinococcus cysts.
Symptoms:
As in other forms of jaundice, the mucous membrane and unpigmented skin, urine and lymph are intensely bile stained. The tests of urine have been mentioned already. The animal is very dull and debilitated. Appetite is disturbed, vomiting in dogs, there is often marked thirst, tongue is furred and there is bad smell from the mouth.
Temperature and pulse vary, there is usually constipation at first and feces are stinking and clay coloured. The course of this condition varies and tends to bring about loss of condition and weakness and death may occur in a few days or weeks. The chronic cases are unfavourable.
Treatment:
Keep the animal warm. Give food which is free from fat. Give laxative. In dogs, give apomorphine in order to cause abdominal compression thus forcing bile into the duodenum, Profuse quantity of glucose water should be given, and even if necessary, intravenous injection of normal saline with dextrose may be given. Liver tonics may be given.
Liver: Disease # 3. Haemolytic Jaundice:
Differs from the catarrhal jaundice in that, there is no obstruction but the symptoms of jaundice and associated with other symptoms such as Poioplasmosis or Trypanosomiasis, Influenza, Distemper, Azoturia etc. in which there is such rapid destruction of R. B. C.s that R. E. System is unable to metabolise the products and they become absorbed into the blood stream. There is often a tendency to constipation but there is no want of absorption of fat.
Treatment:
In these cases, treatment is specifically directed against the cause. In toxic or infectious jaundice, there is always fever in bacterial diseases (Septicaemia and Toxaemia) and in addition to the treatment recommended for biliary congestion, attention is paid to the cause of the trouble. In poisoning, antidotes are recommended where available.
Hepatitis:
Usually preceeded by active congestion. Similar to acute fatty degeneration but in acute attack of hepatitis, there may be little haemorrhage. It is a secondary condition but may be associated with certain poisons, such as phosphorus, arsenic etc. or liver flukes. It may also result from bacterial or viral invasion or Toxemia.
Symptoms:
There is great weakness and fever, sometimes flinking on percussion over the liver which may be enlarged. Appetite is poor, there is thirst and in the dog—vomiting. In the later stage only is the loss of condition and jaundice. In the dogs, small haemorrhages may be noted on the gums. The urine will show the presence of bile and Indican.
Necropsy findings:
The liver in Hepatitis is usually enlarged and the edges swollen but the appearance of the hepatic surface and cross- section varies with the cause. In acute toxic and trophopathic Hepatitis, the lobulation is more pronounced and the liver is paler and redder in colour. The accentuation of the lobular appearance is caused by engorgement of the centrilobular vessels or centrilobular necrosis.
There may be accompanying lesions of jaundice, edema and photosensitization. In Infectious Hepatitis, the lesions are inclined to be patchy and even focal in their distribution. Parasitic Hepatitis is obviously traumatic and focal hemorrhages under the capsule and the necrosis and traumatic injury defineable as tracks.
Congestive Hepatitis is marked by the severe enlargement of the liver, engorgement with blood and marked accentuation of the lobular pattern by vascular engorgement and fatty infiltration of the parenchyma. In hepatic fibrosis, the liver may be grossly enlarged or be much reduced in size with marked lobulation of the surface.
Treatment:
Same as for biliary congestion but in addition in infectious diseases, internal antiseptics are used.
Liver: Disease # 4. Suppurative Hepatitis or Liver Abscess:
Most common in cattle but is met with in other animals also. It is due to pyogenic bacteria which have entered the liver by various routes, e.g. through the umbilical vein in ‘Naval-ill’, by the portal vein from the bowels or otherwise from the blood stream in pyaemia. By means of foreign bodies which have penetrated the liver from the stomach or Reticulum in cattle or which have passed from duodenum to the bile duct or from liver flukes.
Symptoms:
Obscure and often remain unnoticed. In some cattle, no symptoms may have appeared during life and the abscess may have become a chronic one. Where the abscesses are either large, acute or multiple, the symptoms most commonly seen are rigors, irregular but persistent fever, jaundice, digestive disorders. Swelling and sensitiveness over the liver. Prognosis is hopeless. The abscess may be simple and numerous and vary in size. When single it is up to the size of an apple or coconut.
Treatment:
Destruction of animal.
Liver: Disease # 5. Cholelithiasis or Gall Stone:
Uncommon but are said to be more frequent in animals with a gall bladder.
Etiology:
The development of gall stones is associated with stasis with flow of bile and with the appearance of nuclei around which the bile salts may be deposited. In cattle, gallstones are associated with Liver fluke disease. The nuclei being provided by the liver fluke eggs and catarrhal products. In other animals, nuclei are provided by catarrhal products.
A few cases, foreign bodies may be introduced into the bile duct from the duodenum and act as a nuclei. The structures and compounds composing the gall stones are cholestrin, mucus, bile pigments and bile salts. The gall stones usually develop chiefly in the large bile ducts and gall bladder.
They may be single or multiple. The multiple calculi may be as numerous as 600, are very small, shot like and faceted. The single calculus is cylindrical or rounded and may be up to the size of a hen’s egg. Usually rough on the surface—they are usually broken down, are laminated and yellowish brown or green in colour.
Symptoms:
Sometimes, these calculi give rise to no symptoms. If they obstruct the flow of bile, they cause a capricious appetite, irregular bowels, tympanitis, wasting and anaemia. On examination of the urine, there may be found bile pigments and bile salts. Biliary colic will develop, if the calculus obstructs the gut. This may remain for a day or two and reappear at intervals. If colic persists for long, jaundice is observed. Bowels are irregular, vomiting, sensitiveness over liver. Death may occur from Cholemia or rupture of liver and peritonitis.
Treatment:
When colic appears, give antispasmodics and laxative. After an attack, follow a moderate diet and give plenty of water.
Liver: Disease # 6. Cirrhosis of Liver:
Synonym:
Chronic interstitial hepatitis.
New fibrous growth develops in the liver along the course of the bile ducts and around and between liver lobules.
Etiology:
Animal parasites such as Liver flukes and most common in sheep and cattle, occasionally other animal parasites such as Echinococcus polymorphus and other tape worm cysts, various vegetable poisons. In human beings, it has been attributed to ingestion of alcohol. Damaged or mouldy foods are also suspected. Cirrhosis of liver is sometimes observed in dogs, cats and poultry, in which no poisonous plants are suspected as the causes. These cases have been attributed to some toxic products absorbed from the bowels.
Symptoms:
Develop insidiously. The animal become weak and unthrifty, appetite is poor and bowels irregular. Mucous membranes are pallid and only slightly yellow. This may pass on to actual emaciation. In so called cirrhosis, the enlarged liver may be made out on percussion in the right side. This may lead to Ascites. In some cases, there may be marked weakness. As to the course of the disease, it is progressive and may last for months.
Prognosis:
Unfavourable.
Treatment:
Give nourishing diet and tonics. If Ascites develop, tap it.