In many cases the liver is ill secondarily to a problem elsewhere in the body.
Animals that receive a severe and blunt blow to the front of the abdomen can suffer from liver disease. The most common cause of this type of blow is being hit by a car. A liver lobe can be fractured and bleed into the abdomen, even leading to death. A more common occurrence is a bruise (contusion) that heals itself. Heatstroke, diaphragmatic hernia and liver lobe torsion can also cause liver problems.
An inflamed liver is called hepatitis. Trauma can cause this, along with drugs, viruses, bacteria, bile, and toxins.
The severe inflammatory process that occurs with digestive enzymes can spill over into the liver and cause severe disease.
Hemolytic anemia can decrease the oxygen available to liver cells and lead to their death.
Bacteria, viruses, and fungi can all cause liver disease. Since bacterial infection is common in many liver problems it is routine to use antibiotics when treating liver problems. Specific diseases include Infectious canine Hepatitis, canine Herpesvirus, Feline Infectious Peritonitis (FIP), Leptospirosis, abscesses, histoplasmosis, coccidiomycosis, and Toxoplasmosis.
These worms can block blood flow into the liver and cause liver failure. Any disease that can cause failure of the right side of the heart can also cause liver problems.
There are literally thousands of chemicals that could be toxic to the liver. A few examples of these chemicals that are commonly used to treat ill animals include:
- Rimadyl (arthritis treatment) in Labradors
- Thiacetarsamide (heartworm treatment)
- Ketaconazole (fungal treatment)
- Tylenol (acetaminophen)
- Glucocorticoids (cortisone)
- Anthelmintics (worming medication)
- Phenobarbital (epilepsy medication)
Cancer can arise directly within the liver (primary) or spread from elsewhere (metastatic or secondary) through the circulatory or lymphatic systems. In the anatomy section we mentioned the dual blood supply to the liver; the portal vein and the hepatic artery. This extra blood supply increases the chance that a tumor in a different organ that has spread into the bloodstream will end up in the liver. As mentioned in the physiology section, liver cancer is usually detected only after the disease is well established, since functional reserve capacity allowed the liver to function normally for a prolonged period of time.
Some of these liver cancers include:
Metabolic diseases that cause secondary liver problems:
- Diabetes Mellitus
- Inflammatory Bowel Disease
- Protein-losing enteropathy