There are two types of dog liver cancer – a primary liver cell cancer, and a secondary tumor which has spread from another part of the body such as the mammary gland. In this article, we will only discuss primary liver cancer.
Cancer of the liver occurs most frequently in elderly dogs. In fact, over 80% of dogs affected by this type of cancer are over 10 years of age. In almost one-third of dogs that are diagnosed with primary liver cancer, they have no symptoms of the disease. Their cancer is an incidental finding when they are taken to their veterinarian for some other reason.
Those dogs that do have symptoms of cancer show signs of liver disease. These include vomiting, increased thirst and yellowing of the skin, gums and conjunctiva. As the tumor grows, their abdomen may appear swollen.
Your veterinarian will suspect some form of liver disease based on these symptoms, and will run some blood tests to make sure they are on the right track. They are looking for high levels of liver enzymes in your dog’s blood. This may not mean your dog has cancer, but definitely indicates that their liver isn’t working properly.
The next step in getting an accurate diagnosis is to have an ultrasound of your dog’s abdomen, so their liver can be examined. Dog liver cancer can show up in two forms. Firstly, there may be many small cancerous nodules distributed throughout the liver. Secondly, there may be one large tumor affecting just one lobe of the liver.
A biopsy of the liver tumor will identify the exact type of cancer, and give you a better idea of your dog’s prognosis. This can be done in two ways. Firstly, a biopsy needle can be guided by ultrasound into the tumor, and a sample removed for examination. The second method is by fine needle aspirate biopsy. This is safer for those dogs with extensive dog liver cancer, because if the liver isn’t working well it can affect the ability of the blood to clot. A fine needle biopsy has less risk of hemorrhage.
If the cancer is confined to one lobe of the liver, the median survival time for dogs suffering from primary liver cancer is around 3 years. The mass can be surgically removed and the patients tend to do well for quite some time.
The outlook for those with the nodular form of liver cancer isn’t good.
If you own a senior dog, and they start to become unwell with vomiting and excessive drinking, it’s important to rule out dog liver cancer.
Has your dog been diagnosed with cancer? Perhaps you suspect he might have this dreaded disease…