Issue Description Primary liver cancer is rare, comprising less
than two percent of all cancer seen in these species. When it does
occur, the most common primary liver tumors seen in dogs are
hepatocellular carcinomas, which are malignant tumors that arise from
the liver cells, and hepatocellular adenomas or hepatomas, which are
benign tumors that arise from the liver cells. Other Names Liver Cancer, Canine Liver Cancer, Hepatic Neoplasia, HCC, Malignant Hepatoma
Causes Primary liver cancer is the result of a primary
liver tumor (one that originates in the liver). The most common
primary liver tumor is the hepatocellular carcinoma which usually does
not spread to other parts of the body. Instead, the tumor invades into
the liver tissue.
Primary liver cancer is less common than
metastatic liver cancer in dogs. Primary liver cancer occurs more
frequently in older dogs (10 years of age or older). There is a
slightly increased risk of primary liver tumors in male dogs. Although
rather rare, primary liver cancer in dogs can also metastasize to
other parts of the body.
Metastatic, or secondary, liver cancer is one that has spread to the
liver from other organs. Metastatic liver tumors are generally
The liver is the largest organ in the dog's body, and it is involved
in a large number of bodily functions and processes. In particular,
the liver is one of the main organs responsible for detoxifying many
toxic substances circulating in the body. It is understandable,
therefore, that the liver is one of the primary targets of almost all
metastatic cancers. Cancer that metastasizes tends to travel to the
liver through the blood stream or the lymphatic system, and the fact
that the liver is supplied blood through two blood vessels instead of
one makes it all the more vulnerable. The cause of primary liver
cancer may be related to environmental factors, such as exposure to
cancer-causing chemicals (carcinogens). Examples of possible
carcinogens include chemicals in some commercial pet food (food
additives, artificial coloring and flavors), certain pesticides, dyes,
Symptoms Liver cancer in dogs can happen at any age. In
younger dogs and puppies there is a greater possibility of liver
shunt, toxicity and viral diseases. In older dogs, inflammation and
cancer is more probable than other conditions. Even though liver
cancer does not show specific symptoms, severity of the symptoms below
demands additional investigation to eliminate prevalence of
The most common symptom loss of appetite. Anorexia frequently
contributes to a weight loss and improper metabolism of fats,
carbohydrates and proteins further complicates an already complex
situation. Poor appetite also causes anemia. Anemia can also be caused
by disease in liver cells.
Increase in urination and excessive thirst is commonly associated
with other diseases like diabetes and kidney diseases but is one of
the important indications of prevalence of liver cancer in dogs.
Light colored feces can be an indication of liver cancer as a
tumor prevents the secretion of normal bilary pigments into the
Clotting of the blood is one of the important functions of the
liver. Liver cancer in dogs can suppress this function and cause
If the tumor is large enough, it can be found by probing the
region from outside. A distended stomach and abdominal pain can also
suggest liver cancer.
In serious conditions, liver cancer leads to jaundice. If the
mucous membranes are yellowish or the dog is passing orange colored
urine, it is a sure signal of jaundice and should be taken to the vets
for an examination.
Diagnosis While sophisticated diagnostics, including body
scans, can help to identify potential tumours, a sample of tissue from
the suspected area is necessary for an accurate diagnosis of cancer.
Small tumours may simply be removed, but for larger ones, your vet may
either take a small piece of suspect tissue (a biopsy), or use a
needle and syringe to withdraw a sample of cells to be analysed.
Cancers generally occur later in life, but can also affect younger
individuals. Early diagnosis is vital, and dogs over seven years old
should have yearly preventative veterinary examinations.
Treatment Treatment for cancer is pretty general for all
forms. The vet will look at the size of the tumor and decide if
surgery is an option. You may not want an invasive procedure as well.
Keep in mind that if surgery is an option it usually is the best thing
to do to help your dog feel better. If the mass is too large surgery
will not be an option and the vet will recommend medication,
radiation, and/ or chemotherapy. The medications and therapy are to
help reduce the cancer cells as well as prevent more cells from
forming. It is important to realize that radiation and chemotherapy
can last for several treatments before you will see results. In some
cases the cancer may be too far along to do much good. It is always
best to help make the dog as comfortable as possible.
Prognosis It is difficult to detect liver cancer in its
early stages, and prognosis of the advanced stage is extremely poor.