GENERAL DISCUSSION.—The liver is one of the most important glands of the body, as well as the largest. Because of its physiological influence over the functions of the kidneys, intestines, and body in general and the varied functions that it possesses, it is frequently affected by functional disorders.

All of the blood that comes directly from the intestine is received by the liver. It secretes the bile, neutralizes many of the poisonous substances and end products of digestion that are taken up by the absorbing vessels of the intestine, and acts as a storehouse for the glycogen.

It can be readily understood from this brief statement of the nature of the liver functions, that any functional disorder of the liver may be far reaching in its effect. In many of the diseases that involve other organs, the liver may be primarily affected. It is difficult to diagnose functional disorders of the liver that are responsible for a diseased condition of some other body organ. A knowledge of the physiology and pathology of the liver is of the greatest importance in the diagnosis of this class of disorders.

In the larger domestic animals, symptoms of liver diseases are more obscure than in the small animals. In certain parasitic diseases and in mixed and specific infectious diseases, the liver may show marked pathological changes.

COMMON CAUSES OF LIVER DISORDERS.—Domestic animals commonly live under very unnatural conditions. Ill results do not follow unless these conditions are so extreme as to violate practically all of the health laws. Pampered animals are especially prone to liver disorders. The feeding of too heavy and too concentrated a ration together with insufficient exercise is one of the most common causes of disorders of the liver. The feeding of a ration that is unsuitable for that particular species is a common source of disease in animals. For example, the feeding to carnivora of a ration made up largely of starchy feed, and the feeding of a ration containing an excessive quantity of protein to herbivorous animals may result in intestinal, liver and nervous disorders. Spoiled feed may prove highly injurious. Catarrhal inflammation of the intestine and intestinal parasites may obstruct the bile duct, and interfere seriously with the functions of the liver.

Symptoms.—In diseases of the liver the appetite is irregular or the animal refuses to eat, is constipated, or has diarrhoea. The faeces may be grayish colored or foul smelling. Colicky pains are sometimes manifested. Usually the animal acts dull and weak. A raise in body temperature may be noted. The visible mucous membranes may appear yellowish- or brownish-red in color.

Treatment.—Animals grazing over well drained pastures that are free from injurious weeds and provided with plenty of drinking water, seldom develop diseases of the liver. Exercise, a natural diet and plenty of clean water, as well as preventing liver disorders, may be classed among the most important of all curative agents. Laxatives or cathartics, such as oils, salts, aloes, and calomel, in small doses may be given. We prefer the administration of oil or aloes to horses, Glauber's or Epsom salts to ruminants, and calomel to dogs. The administration of minimum doses of these drugs, and repeating the dose after a short interval, is preferable to large doses. Alkaline tonics are also indicated. The following mixture may be given: bicarbonate of soda, sulfate of soda and common salt, eight ounces of each, and powdered gentian and sulfate of iron, four ounces of each. Large animals may be given a small tablespoonful of this mixture with the feed three times a day. The dose for sheep and hogs is one teaspoonful. A very light, easily digested ration should be fed.

QUESTIONS

1. What can be said of the importance of the liver?

2. Tell something of its duties as a gland.

3. In what animals are liver troubles most conspicuous when present?

4. Give causes of liver disorders.

5. What are the symptoms?

6. What are the most important natural cures?

7. What rule may be given for adapting suitable laxatives to different classes of animals?