Liver cancer in dogs is quite rare, accounting for only about 1% of all canine tumors, and it most commonly affects older dogs. One of the biggest challenges with this disease is early detection. Symptoms often develop slowly and may not appear until the cancer is already advanced. As a result, many dogs are diagnosed only after the cancer has grown large or spread to other areas.
Canine liver cancer can be primary or secondary (metastatic). Primary liver cancer starts in the liver itself, most often in liver cells (hepatocellular tumors) or bile duct cells. Metastatic liver cancer begins in another part of the body—such as the spleen, pancreas, or gastrointestinal tract—and then spreads to the liver.
The outlook, or prognosis, varies widely and depends on several factors, including the type of cancer, tumor size, whether it has spread, and the treatment options available. Some liver tumors grow slowly and may be managed successfully, while others are more aggressive.
If you notice concerning signs such as vomiting, reduced appetite, unexplained weight loss, low energy, abdominal swelling, yellowing of the gums or eyes (jaundice), or increased thirst or urination, it’s important to contact your veterinarian promptly. These symptoms can be linked to liver disease and may signal the need for immediate evaluation and diagnostic testing. Early veterinary care can improve comfort, guide treatment decisions, and, in some cases, extend your dog’s quality of life.
Understanding Liver Cancer in Dogs
The liver is a vital organ that supports your dog’s digestion and many essential body functions. It helps process nutrients, remove toxins from the blood, regulate metabolism, and produce bile, which is necessary for digesting fats. Because the liver plays such a central role in overall health, diseases affecting it—such as cancer—can have widespread effects.
Liver cancer can develop from different types of cells. Primary liver cancers, such as hepatocellular carcinoma in dogs, begin in the liver itself and usually arise from liver cells or bile duct cells. Less commonly, cancers like hemangiosarcoma originate elsewhere in the body and later spread to the liver.
Primary liver cancer starts in the liver and is relatively uncommon in dogs. These tumors often appear as a single, large mass rather than multiple small liver nodules in dogs. In some cases, if the cancer has not spread, surgery may be an option to remove the affected portion of the liver. It’s also important to note that many tumors found in a dog’s liver are benign, meaning they are not cancerous. Primary liver cancers are most often diagnosed in older dogs.
Secondary (metastatic) liver cancer begins in another part of the body—such as the spleen, lungs, pancreas, or gastrointestinal tract—and then spreads to the liver through the bloodstream or lymphatic system. This form is more common than primary liver cancer and is usually more challenging to treat, as it often involves multiple organs.
Understanding whether liver cancer is primary or secondary helps veterinarians determine the best diagnostic approach, treatment options, and overall outlook for your dog.
Types of Liver Tumors in Dogs
Type of Liver Tumor in Dogs | Benign or Malignant | How Common Is It? | Description | Treatment & Outlook |
Hepatocellular carcinoma (HCC) | Malignant | Most common primary liver cancer in dogs; mainly affects older dogs and accounts for about 50–70% of primary liver tumors | Usually appears as a single, large mass and often grows slowly. Spread to other organs is less common compared to other cancers | Surgery is often effective if the tumor is localized; prognosis can be good after complete removal |
Bile duct carcinoma (cholangiocarcinoma) | Malignant | Second most common primary liver cancer in dogs; still rare overall | Aggressive tumor that spreads quickly and may block bile ducts, causing jaundice | Prognosis is guarded to poor; treatment may include surgery, chemotherapy, and palliative care |
Sarcomas (hemangiosarcoma, leiomyosarcoma, fibrosarcoma) | Malignant | Uncommon as primary liver tumors but hemangiosarcoma frequently spreads to the liver | Highly aggressive and fast-spreading; may cause sudden internal bleeding or abdominal masses | Surgery may be possible in select cases; chemotherapy and supportive care are often recommended |
Lymphoma and mast cell tumors | Malignant | Relatively common as metastatic disease; primary liver involvement is uncommon | Usually spread to the liver from another primary cancer site and may appear as nodules or diffuse enlargement | Chemotherapy is the main treatment; surgery is rarely helpful |
Benign adenomas and cysts | Benign | Quite common in older dogs | Non-cancerous nodules or fluid-filled cysts that often cause no symptoms | Surgery is only needed if they grow large or cause discomfort |
What Causes Liver Cancer in Dogs?
There is no single known cause of liver cancer in dogs. Experts believe it arises from a combination of factors, including genetics, age, and environmental influences. Most cases occur in older dogs, typically over 9–10 years of age.
Some factors that may contribute include:
Chronic liver inflammation – long-term liver disease or injury can increase cancer risk
Exposure to toxins – certain chemicals or medications may play a role
Hormonal imbalances – though evidence is limited
Current research shows that breed and gender do not significantly affect risk, meaning any dog can potentially develop liver cancer. While the exact triggers are still being studied, regular veterinary check-ups and early attention to liver-related symptoms can help catch problems sooner.
Symptoms of Liver Cancer in Dogs
In the early stages, a dog liver tumor often shows no obvious signs, making it difficult to detect. As the disease progresses, you may notice:
Symptom Category | Symptoms | Notes |
General | Tiredness, reduced appetite, weight loss | Early stages may be subtle |
Abdominal | Swelling, “pot-bellied” appearance, pain | Monitor closely |
Jaundice | Yellowing of eyes or skin, pale gums | Indicates liver dysfunction |
Emergency | Sudden weakness, collapse, very pale gums | May signal internal bleeding – seek immediate care |
Some symptoms can indicate a medical emergency. Sudden weakness, collapse, or very pale gums may signal internal bleeding from a ruptured liver tumor, which requires immediate veterinary care.
Keeping a symptom log with dates and details can help your veterinarian diagnose the problem faster and choose the most appropriate tests or treatments.
How Liver Cancer in Dogs Is Diagnosed
Veterinarians diagnose canine liver cancer through a step-by-step approach:
Physical Exam – The vet may feel your dog’s abdomen for swelling, a firm mass, or other abnormalities.
Blood Tests – These help check liver enzyme levels, detect anemia, and assess overall organ function.
Imaging – Tools like ultrasound or X-rays allow the vet to see the size of the tumor and whether it has spread to other organs.
Needle Sample or Biopsy – A small tissue sample may be taken from the liver to confirm the presence of cancer.
Microscopic Examination – Examining the tissue under a microscope helps identify the exact type of liver cancer. This is considered the most accurate test for diagnosing liver tumors.
Early and thorough testing can guide treatment decisions and improve outcomes for dogs with liver cancer.
Liver Cancer in Dogs Treatment
Treatment | When Used | How It Works | Notes / Prognosis |
Surgery (Lobectomy) | Tumor confined to a single lobe | Removes affected liver portion; liver regenerates | Most effective option; short-term hospitalization required; regular follow-up needed |
Stereotactic Radiation Therapy | Surgery not possible | Focused radiation targets tumor, sparing healthy tissue | Fewer side effects than chemo; can shrink or destroy tumor |
Chemotherapy | Multiple lobes affected or metastasis | Drugs target rapidly dividing cancer cells | Often palliative; effectiveness depends on tumor type |
Supportive / Palliative Care | Any stage | Diet modification, medications to control nausea, stimulate appetite, manage pain | Focuses on comfort and quality of life; used alongside other treatments |
Surgery
Surgery is the most effective treatment when the liver tumor is confined to a single lobe. In this procedure, called a lobectomy, the veterinarian removes the affected portion of the liver.
The liver has a remarkable ability to regenerate, which allows it to regain normal function after surgery. Most dogs require short-term hospitalization to recover safely.
After surgery, the vet will usually recommend:
Regular blood tests to monitor liver function
Follow-up imaging (ultrasound or X-rays) to check for tumor recurrence
When detected early and removed successfully, surgery can significantly improve prognosis and quality of life for dogs with liver cancer.
Stereotactic Radiation Therapy
Stereotactic radiation therapy is a non-surgical treatment that uses highly focused radiation to target liver tumor in dogs with precision, minimizing damage to surrounding healthy tissue.
Veterinarians often recommend this option when surgery is not possible due to the tumor’s location or the dog’s overall health. Compared to chemotherapy, it usually causes fewer side effects.
Over time, this treatment can shrink the tumor or destroy cancer cells, helping to control the disease and improve the dog’s quality of life.
Chemotherapy
Chemotherapy is used when liver cancer affects multiple lobes or has spread to other organs. Its effectiveness depends on the type of tumor. For example, cancers like lymphoma often respond well to chemotherapy, while others, such as hemangiosarcoma, are more resistant.
In most cases, chemotherapy cannot cure the cancer but can help slow its progression and relieve symptoms, improving the dog’s comfort and quality of life.
Supportive and Palliative Care
For dogs with liver cancer, comfort and quality of life are the primary goals. Veterinarians may recommend:
Special diets low in copper and with moderate protein to support liver function
Medications to control nausea, stimulate appetite, and manage pain
Regular veterinary check-ups are important to monitor the dog’s condition and adjust care as needed.
Supportive and palliative care helps ensure that, even if the cancer cannot be cured, your dog remains as comfortable and active as possible.
How Long Can a Dog Live With Liver Cancer?
How long a dog can live with liver cancer depends on the tumor type and available treatments.
Benign tumors often have an excellent prognosis and can usually be cured with surgery.
Dogs with a large hepatocellular carcinoma confined to a single liver lobe may live 1–3 years after successful surgery.
More aggressive, nodular, diffuse, or metastatic cancers generally have a shorter outlook, often several months to about a year even with treatment.
Early diagnosis and surgical removal of the tumor can greatly improve survival. Throughout treatment, focusing on comfort, close monitoring, and regular veterinary care can help maintain your dog’s quality of life and wellbeing.
Living With a Dog Diagnosed With Liver Cancer
A liver cancer diagnosis can feel overwhelming, but setting realistic expectations and taking things one day at a time can help you and your dog cope.
Monitor daily habits such as appetite, water intake, energy levels, and comfort.
Maintain a gentle routine and allow light exercise if your dog feels up to it.
Work closely with your veterinarian for regular check-ups, blood tests, and imaging to track the dog’s condition.
With proper care, support, and attention to comfort, many dogs with liver cancer can continue to enjoy happy and comfortable lives for months or even years.
Final Takeaway
Liver cancer in dogs is relatively uncommon, but understanding the disease can make a real difference in your pet’s health. Early detection is key, as it improves treatment options and outcomes—particularly for tumors that can be removed surgically.
While some liver cancers are aggressive, others are treatable, and modern therapies like surgery, radiation, and chemotherapy continue to provide hope. With attentive veterinary care, timely treatment, and lots of love, many dogs can continue to enjoy a comfortable and meaningful life even after a liver cancer diagnosis.
Frequently Asked Questions
Is liver cancer painful in dogs?
Liver cancer can cause pain, particularly as the tumor grows or spreads. However, many dogs show little or no discomfort in the early stages.
Can a liver tumor occur naturally in dogs?
Yes. Liver tumors can develop naturally, especially in older dogs. Most arise without a clear cause and are not linked to injury or infection.
What are the signs of end-stage liver failure in dogs?
End-stage liver failure in dogs can cause severe weakness and lethargy, along with loss of appetite, vomiting, and weight loss. Dogs may also develop abdominal fluid buildup, yellowing of the eyes or skin (jaundice), confusion or seizures, and changes in urine and stool, such as dark urine and pale-colored stools. These symptoms indicate a serious medical condition that requires immediate veterinary attention.
