Structure and Function of the Liver in Dogs

Below is information about the structure and function of the canine liver. We will tell you about the general structure of the liver, how the liver works in dogs, common diseases that affect the liver and common diagnostic tests performed in dogs to evaluate liver function. Many diseases of the liver begin with “hepatic” which means liver. For example, “Hepatopathy” means disease of the liver and “Hepatitis” means inflammation of the liver.

What Is the Liver?

A dog’s liver, a very complex and hard working structure, is the largest organ in the body. The liver filters the blood and has hundreds of other functions, most of which are necessary to live and are not done elsewhere in the body. Every part of the liver can perform all its tasks and is the only organ in the body with this capability. The liver has an amazing ability to recover from injury and regenerate new tissue.

Where Is the Liver Located in Dogs?

The liver is a multi-lobed organ located in the front of the abdominal cavity. It lies directly behind the diaphragm (the muscle that aids in breathing and separates the chest from the abdomen) and directly in front of the stomach. The liver is positioned horizontally across the front of the abdomen, with proportionally more of the liver on the right side.

What Is the General Structure of a Dog’s Liver?

The normal liver is a deep red color with a firm consistency. It is divided into several different lobes, and each lobe is made up of multisided units called hepatic lobules. Each lobule is composed of a curved sheet of cells, which enclose numerous blood-filled cavities known as sinusoids. These sinusoids give the liver a spongy texture and enable it to hold large amounts of blood.

Two major blood vessels enter the liver: The portal vein carries most of the blood to the liver and contains nutrients from the gastrointestinal tract, as well as chemicals and drugs that have been absorbed into the body. The hepatic artery carries oxygen-rich blood to the liver from the heart and lungs.

Two major conducting structures exit the liver. The hepatic veins drain blood from the liver. The bile ducts take bile from the liver cells to the gall bladder, a pear-shaped pouch located under the liver.

What Are the Functions of the Liver?

The liver regulates the levels of many different chemicals and substances in the blood, and it excretes bile, a yellowish-green digestive fluid. All the blood leaving the stomach and intestines passes through the liver. The liver processes this blood and breaks down the nutrients, chemicals, and drugs into forms that are easier for the rest of the body to use. There are more than 500 vital functions associated with the liver. Some of these functions include the following:

What Are Common Diseases of the Liver in Dogs?

Since the liver is involved in many biochemical processes, many different diseases can affect it. A variety of clinical signs may be seen with liver disorders; however, in many cases, one of the earliest signs of disease is jaundice. Jaundice occurs when the blood contains an excessive amount of bilirubin, causing a yellow color to the skin, gums, and sclera (whites of the eyes). Ascites (fluid in the abdominal cavity), another clinical sign seen with liver disease, occurs when there is impairment of blood flow through the portal vein. This leads to hypertension (high blood pressure) in the portal vein, which causes fluid to leak out of the portal vein into the abdomen. Low albumin protein levels in the blood from liver disease may also cause ascites.

The liver has a remarkable ability to produce new cells to replace its own diseased or damaged cells. This regenerative capability allows the liver to return to normal function in some cases.

Some examples of liver diseases include:

What Types of Diagnostic Tests Are Used to Evaluate the Liver?

There are many diagnostic tests that are helpful when evaluating the liver.