Liver – an introduction
Liver is one of the most important and complex organs that carries several vital functions like it stores nutrients, detoxifies blood, etc and has a tremendous capacity to regenerate. Liver can easily perform its functions even though after 70-80 percent of liver mass is affected by the disease/infection.
Anatomy and physiology of liver
Dog liver is normally deep red to reddish brown in colour with a firm consistency and is divided into several lobes. The chief functional cells of liver are called the heptocytes. The portal vein carries blood, nutrients and drugs and hepatic artery carries oxygen rich blood to the liver, hepatic veins drain blood form the liver and bile duct takes bile from liver cells to the gall bladder.
Liver performs many vital functions of which the most important are:
- Metabolism of carbohydrates, proteins and fat.
- Detoxification of waste.
- Vitamin production and storage.
- Manufacturing digestive enzymes.
- Storage of nutrients.
- Production of blood clotting factors.
Diseases of liver in dogs
Most of the liver diseases are secondary to a problem elsewhere in the body. Major factors that can cause liver disease include:
- Inflammation- Inflammation can occur due to many reasons like trauma, drugs, viruses, bacteria, bile, and toxins, which usually leads to hepatitis.
- Infection- Bacteria, viruses, and fungi can cause liver disease. Specific diseases include infectious canine hepatitis, canine herpesvirus, feline infectious peritonitis (FIP), leptospirosis, abscesses, histoplasmosis, coccidiomycosis, and toxoplasmosis.
- Heartworms- These worms can block blood flow into the liver and cause liver failure.
- Toxins- Toxins through food and water as well as drugs used for treating illness can affect liver. For example, drugs like Ketaconazole, Acetaminophen, Glucocorticoids, Anthelmintics and Phenobarbital, etc.
- Anaemia – Haemolytic anaemia can decrease the oxygen available to liver cells and lead to their death, thus causing liver damage.
- Pancreatitis- The severe inflammatory process that occurs with digestive enzymes can spill over into the liver and cause liver damage.
Common symptoms observed in liver diseases
Symptoms of liver diseases are variable and subtle in the early stages of the problem. Some of these include:
- Loss of appetite, vomition, nausea and diarrhoea.
- Ascites-accumulation of fluid in the abdomen.
- Yellowing of skin and mucous membrane (jaundice).
- Pain associated with abdomen.
- Increased water consumption and excessive urination.
Treating liver diseases
Liver disease is a serious medical condition in dogs and it is very important to identify the primary cause at early stages, because liver failure will be exhibited only after 70- 80 percent of cells are damaged. When a dog is presented to the vet, complete history, followed by the physical examination for observable abnormalities such as distended abdomen, dehydration, signs of jaundice, etc are usually carried out. A comprehensive assessment of liver enzymes that include alanine transaminase (ALT) and aspartate transaminase (AST), alkaline phosphatase (AP) and gamma glutamyltransferase (GGT) is must when suspected or tentatively diagnosed for liver ailment.
Diagnosing liver disease in dogs requires a number of tests that typically are conducted in a specific order over an extended period of time. Using a combination of history, physical examination, blood, urine, faecal tests, coagulation profiles, diagnostic imaging and tissue sampling tests, a veterinarian should be able to assess the nature and extent of a dog’s liver condition, so that an appropriate treatment protocol can be implemented.
The key to effective treatment in liver disease depends upon treating the primary conditions or removing the cause of the disease. Physical activity is usually kept minimal and special diet low in proteins is recommended.
(Dr Ritesh Sood is Product Manager at the Himalaya Drug Company. For further info, e-mail at: firstname.lastname@example.org).