Liver Cancer in Dogs: Symptoms, Diagnosis, and Treatment

Liver Cancer in Dogs

Liver Cancer in Dogs: Symptoms, Diagnosis, and Treatment

Cancer. Even the word is terrifying. Having a diagnosis of liver cancer or your best friend and companion can be truly awful. Is it all doom and gloom, though? What lies ahead on this terrible journey? 

We will walk you through the terms, problems, and solutions that you will encounter with liver cancer in dogs.

Key Takeaways 

  • There are various types of liver cancer in dogs, including hepatocellular carcinoma (HCC), that affect dogs differently.
  • Symptoms include lethargy, vomiting, diarrhea, weakness, increased urination, excessive thirst, and more.
  • Diagnosis of liver cancer is usually through blood tests, urinalysis, biopsy, or image tests.
  • Treatment can be through surgery, chemotherapy, or natural ways.

Types of Liver Cancer in Dogs

There are two types of tumors that may occur in a dog’s liver [1]. Benign tumors are slow-growing and will pose no real harm to your dog. They can affect younger dogs but are more common in older dogs. 

Malignant tumors grow more rapidly and invade surrounding tissue, causing liver damage. They are more serious and need medical intervention.

Your vet may use many confusing terminologies, so let’s break it down into bite-size chunks for you to digest. 

Primary Liver Cancer vs Secondary Liver Cancer

There are two types of cancer of the liver, primary and secondary. This tells you how the cancer started and how it may spread through your dog. 

Primary liver cancer is a type of liver cancer started in the liver itself. A secondary tumor is metastatic cancer that originated in a different organ and then spread (metastasized) to the liver later. 

Typical sources for a secondary tumor include lymphoma, osteosarcoma, pancreatic cancer, intestinal carcinoma, transitional cell sarcoma, or thyroid cancer. Any form of metastasized cancer is more serious as it indicates at least two locations for the tumor.

Hepatocellular Carcinoma (HCC)

Hepatocellular carcinoma tumors are one of the most common cancers in dogs [2]. It usually presents in one of three ways:

  • Diffuse: A cancer spread throughout the entire liver.
  • Nodular: Several discrete masses in the liver.
  • Massive: A single tumor in the liver.

Massive liver tumors are the most common presentation of hepatocellular carcinoma and the easiest to treat. It can usually be removed surgically if it is caught early enough and gives a good prognosis.

Diffuse hepatocellular carcinoma and nodular hepatocellular carcinoma spread throughout the entire liver. They are more difficult to treat, and your vet can advise you on the best way forward. 

liver cancer in dogs The metastatic rate of Hepatocellular Carcinoma (HCC) in dogs
The metastatic rate of HCC in dogs range from 4.8% to 61%
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3743567/

Bile Duct Carcinoma 

Bile duct carcinoma is the second most common type of liver cancer in dogs. It affects the epithelial cells lining the bile duct. It is quite an aggressive tumor, and as it metastasizes (travels to other organs) in 70–87.5% of cases, it will have a poor prognosis [3]

Mesenchymal Sarcoma

You may also hear mesenchymal sarcoma or a mesenchymal tumor referred to as soft tissue sarcoma or STS. They are the third most common type of liver tumor in dogs, accounting for about 15% of all presentations [4].

As their name suggests, they are found in connective tissue and may be present throughout the body, not just the liver. They are locally invasive and have lower rates of metastasis, which is generally good news.  

Neuroendocrine Tumor

Neuroendocrine tissues are those which have hormone-producing functions and neurological ones. The liver is one such organ that may fall foul of this type of canine cancer. 

A NET or a neuroendocrine tumor is quite a rare presentation in dogs. They are slow-growing and metastasize less, which is a good thing, but they usually grow through the whole liver, destroying the tissue and reducing the liver function as they do so. 

Signs of Liver Cancer in Dogs

The problem with liver cancer is that the signs can initially look innocuous, or the dog will just seem a bit down, unlike other more obvious symptoms of cancer in dogs. You know your dog, so pay attention to when they seem a little ‘off color’ and keep an eye on them. 

liver cancer in dogs Common signs of liver cancer in dogs
Lethargy is the most common sign of liver cancer in dogs, followed by inappetence and vomiting
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4431158/

Lethargy

Your dog will generally seem listless and less interested in you and its surroundings. This may come and go; they will have good and bad days, but you will notice a general downhill progression.

Vomiting

Shortly after eating, your dog may bring up its food. Your dog may vomit once or several times or even try to be sick, even though it brings nothing up. 

Diarrhea

One of the symptoms of liver cancer is when your dog goes to the toilet, you may notice looser stools than normal. Your dog may also go, or try to go, more often than usual. 

Increased Urination

Your dog will want to urinate more often than usual as well. He or she will make more frequent pit stops on walks and make less water than usual. They will want to go out more often, as they are unable to ‘keep it in’ like normal. 

Excessive Thirst

Another of the symptoms of liver cancer is that you will see your dog drinking more. This will be long drinks at the water bowl as well as shorter visits for a top-up. 

Loss of Appetite and Weight Loss

Over time your dog will become less and less interested in food. It may seem that your dog has become fussy or doesn’t like the brand of food you have. However, when they start to refuse a range of food, you will know something is not quite right. 

It is normal for a dog’s weight to change slightly, but any dramatic loss is certainly a sign that something is amiss. 

Jaundice (Yellowing of Skin, Eyes, and Gums)

This is a classic presentation of liver disease in dogs, not just liver cancer. The first thing owners will notice is the whites of the eyes becoming discolored. If this is the case, check the gums for confirmation. The skin is less easy to see but is also an indicator. 

Weakness

If you see a change in the overall athleticism in your dog, this may be a cause for concern. They may be less able or unwilling to jump on a bed or on their favorite chair. They may not want to walk upstairs in your house, or they pause halfway up when doing so.

On walks, they will take frequent rests and remain close to you, not wanting to play the usual games. They will not indulge in play with other dogs like normal. 

It should be noted that all the information here does not constitute medical advice. If you are worried, please see your vet. 

What Are the Symptoms of a Dog Dying From Liver Failure?

End-stage or terminal liver cancer in dogs is, sadly, easy to see. People will often say that your dog will tell you when they feel they have reached the end of their journey and are ready to cross the rainbow bridge.

Liver cancer in dogs produces all the typical signs of liver dysfunction. Jaundice is a very common sign, a yellowing of the eyes, gums, and skin. 

They will become tired and show less and less interest in the world around them, looking depressed. You may also see blood in the urine and stools. 

They will suffer from abdominal swelling and abdominal pain. This can be due to the liver enlargement, the cancer itself, fluid retention, or a combination. 

They will increasingly seem to be confused or lost. This is due to a build-up of toxins that the liver would normally filter out. If the liver is not removing toxins as usual, it may also lead to blindness and/or seizures. 

What Causes Liver Cancer in Dogs?

The causes of liver cancer in dogs is not well understood. One of the main markers is age; primary liver cancer and secondary liver cancer are more common in older dogs, typically over nine years. 

Hepatocellular carcinoma has not been linked to any root cause nor breed of dog. There is some evidence that other types of metastatic cancers can be more common in some pedigree breeds, typically German Shepherds, Poodles, Golden Retrievers, and Rottweilers, to name a few [5].

Secondary liver cancer, one that has migrated from another organ, such as mast cell tumors (skin cancer) or mammary carcinoma (breast cancer) mirrors the human progression of the disease. These types of metastatic cancers may occur in younger dogs.

Humans and dogs get many of the same cancers, and around one in four dogs will die from the disease [6]

Dog Liver Cancer Diagnosis

In the early stages, liver cancer in dogs is easy to miss. Many of the common symptoms are vague and indicative of many ailments. This is why it is important for you both to see the vet as soon as you notice anything amiss. 

Your vet has a battery of diagnostic imaging tests to perform to help to diagnose liver cancer and give an accurate diagnosis. As with humans, for a good prognosis, early identification is key. 

liver cancer in dogs

Blood Tests

A simple blood draw will be taken. Your vet will look for markers of liver abnormalities and problems in blood clotting.

Urinalysis 

A sample of urine is tested to look for liver abnormalities that may indicate either chronic inflammation of the liver or the presence of cancerous tumors. 

Imaging Tests

Your vet may decide on either an ultrasound or a radiograph if they feel there may be liver tumors present. They will show how the masses spread.  

This is important in an accurate diagnosis for malignant liver tumors, differentiating between diffuse hepatocellular carcinoma tumors and massive hepatocellular carcinoma. 

Early diagnosis here is the difference between a good prognosis and a poor prognosis. 

Biopsy 

A needle aspiration or fine needle aspiration is a quick and easy way to help in diagnosing liver cancer [7]. A sample of the dog’s tumor is removed with a needle for lab tests. 

The origin of the liver tumors can be established and either surgical removal or other options can be explored. 

Treatment for Liver Cancer in Dogs

The treatment for liver cancer is totally dependent on the type of cancer presenting. Metastatic liver cancer will involve treating the primary cancer and the secondary cancer. 

Your vet will advise you on the best route for both of you. 

Surgery

In primary liver cancer, surgical removal of massive hepatocellular carcinoma is usually effective. If the liver tumors are diffuse or nodular, then the vet will usually explore other options. 

Dog Liver Tumor Surgery Cost

As with all long-term treatments that involve surgery and lab tests, the costs can be high. Insurance is certainly a great idea for pets to keep the bills manageable. 

Chemotherapy

If there are metastatic cancers located in other organs or the tumor is diffuse or nodular, then your vet will recommend chemo rather than surgical removal. 

Chemo is a cocktail of drugs that aim to slow or stop the spread of cancerous tumors. The drugs target rapidly dividing cancerous cells, but unfortunately, this will also be other, normal cells in your pet. This is why dogs can have adverse reactions to chemo. 

Liver Cancer in Dogs: Natural Treatment 

If you choose natural treatments for your dog, it is recommended that you also follow your vet’s prescribed treatment for a good prognosis. 

CBD oil has shown (anecdotally) to be effective in pain relief, stress reduction, and is also reported to have anti-inflammatory properties [8] [9]

You must make sure the oil is suitable for your dog, as human oils have higher THC content which may be toxic for your furry friend. 

Clinical Trials for Dog Liver Cancer

There are numerous ongoing clinical trials, and they change all the time. Due to the range and presentation of liver cancers there is no ‘One Shoe Fits All’ approach. A directory of all current ongoing trials can be found here [10]

Sorafenib 

This is known by the brand name of Nexavar [11]. It is a treatment for primary liver cancer only. It would be prescribed for hepatocellular carcinoma but only in massive tumors. It is not recommended for diffuse tumors.

Dog Liver Cancer Prognosis: What to Expect

As with humans, catching the tumor early is key. With hepatocellular carcinoma presenting as a massive tumor, the prognosis is good. Early surgical removal can cure your dog completely.

With secondary liver tumors, the prognosis can be poor. Metastatic liver cancer is very serious as there will be other organs involved. The prognosis here is, sadly, often poor. 

Dog Liver Tumor Life Expectancy 

With prompt and accurate diagnosis, the average life expectancy with primary hepatocellular carcinoma presenting as massive tumors is expected to be five years plus. 

With hepatocellular carcinoma presenting as either diffuse tumors or nodular tumors, the prognosis is good, if caught in time. 

If the presentation is metastatic liver cancer, the prognosis, even with chemo, is usually poor if not detected quickly. It can be as little as one to three months. 

liver cancer in dogs The typical survival time of dogs diagnosed with HCC
Dogs diagnosed with HCC have a typical survival time of 1,000 days
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4431158/

Liver Cancer in Dogs: When to Euthanize

This must be the hardest choice any dog owner will ever have to make. To send your companion over the rainbow bridge is a heart-rending decision. 

Your vet will outline treatments and possible outcomes. It is then down to you to make the hard choices. You must balance quality of life against your own need not to lose your companion. 

In the end, you can only listen to your dog and do what is best for them. There is no better way to show your love, no matter how hard it is, than to do what is right for them, not you. 

FAQ

Is Liver Cancer in Dogs Painful?

In the early stages, there is little or no pain, which is why it is often so hard to catch early. There will be, in some cases, abdominal pain. As it progresses, discomfort will occur from the loss of liver function. 

How Long Can Dogs Live With Liver Cancer?

This all depends on the type of cancer. Some fast-growing metastatic cancers are very rapid. The masses spread quickly throughout the dog’s liver. Death can occur in a matter of months. 

With hepatocellular carcinoma, it can be slow-growing, and the whole process can take years. 

How Do Dogs With Liver Cancer Die?

With a primary tumor, the cancer is only in the liver. In time, this will cause the dog’s liver to slowly fail and then shut down. Death will be from organ failure. 

With a secondary cancer, other organs will be involved, so it depends on the systems involved and the severity of the separate tumors. 

What Is the Most Aggressive Form of Liver Cancer?

Metastatic cancer tumors have already invaded the liver from their primary source. As such, they are often the most rapidly invasive forms of cancer. They can present in a number of different ways, as detailed above.

Conclusion

Having dogs as your companions is one of the most rewarding experiences. Their love and devotion literally shine through in almost everything that you do together. 

Cancer in dogs can be tough, but many pets manage to pull through and recover to live many more happy years. When it comes time for you to be there for them and make the decisions that they can’t, you have to be strong. They love you unconditionally, and now it is time for you to do the same, no matter how hard it may seem. 

References

  1. MADEWELL, B.R. “Small Animal Clinical Oncology, 2nd Ed By S.J. Withrow, E.G. MacEwen (Eds).” Veterinary Surgery, vol. 25, no. 4, 1996, pp. 353–354., doi:10.1111/j.1532-950x.1996.tb01425.x. 
  2. Patnaik, A. K., et al. “Canine Hepatocellular Carcinoma.” Veterinary Pathology, vol. 18, no. 4, 1981, pp. 427–438., doi:10.1177/030098588101800402.
  3. Patnaik AK, Hurvitz AI, Lieberman PH, Johnson GF. Canine bile duct carcinoma. Vet Pathol. 1981 Jul;18(4):439-44. doi: 10.1177/030098588101800403. PMID: 6266117.
  4. Prognostic Factors for Cutaneous and Subcutaneous Soft Tissue Sarcomas in Dogs M. Dennis, K. D. McSporran, N. J. Bacon, F. Y. Schulman, R. A. Foster, B. E. Powers, https://doi.org/10.1177/0300985810388820
  5. Dobson J. M. (2013). Breed-predispositions to cancer in pedigree dogs. ISRN veterinary science, 2013, 941275. https://doi.org/10.1155/2013/941275
  6. Davis, B. W., & Ostrander, E. A. (2014). Domestic dogs and cancer research: a breed-based genomics approach. ILAR journal, 55(1), 59–68. https://doi.org/10.1093/ilar/ilu017
  7. Ménard, M, et al. “Fine Needle Aspiration Biopsy of Malignant Tumors in Dogs and Cats: a Report of 102 Cases.” The Canadian Veterinary Journal = La Revue Veterinaire Canadienne, U.S. National Library of Medicine, Dec. 1986, www.ncbi.nlm.nih.gov/pmc/articles/PMC1680429/#:~:text=Fine%20needle%20aspiration%20biopsy%20is,83%20dogs%20and%2019%20cats. 
  8. Gamble, L. J., Boesch, J. M., Frye, C. W., Schwark, W. S., Mann, S., Wolfe, L., Brown, H., Berthelsen, E. S., & Wakshlag, J. J. (2018). Pharmacokinetics, Safety, and Clinical Efficacy of Cannabidiol Treatment in Osteoarthritic Dogs. Frontiers in veterinary science, 5, 165. https://doi.org/10.3389/fvets.2018.00165
  9. Verrico CD, Wesson S, Konduri V, Hofferek CJ, Vazquez-Perez J, Blair E, Dunner K Jr, Salimpour P, Decker WK, Halpert MM. A randomized, double-blind, placebo-controlled study of daily cannabidiol for the treatment of canine osteoarthritis pain. Pain. 2020 Sep 1;161(9):2191-2202. doi: 10.1097/j.pain.0000000000001896. PMID: 32345916; PMCID: PMC7584779.
  10. “Clinical Trials Database.” Veterinary Cancer Society, vetcancersociety.org/pet-owners/clinical-trials/. 
  11. Tang, Weiwei, et al. “The Mechanisms of Sorafenib Resistance in Hepatocellular Carcinoma: Theoretical Basis and Therapeutic Aspects.” Nature News, Nature Publishing Group, 10 June 2020, www.nature.com/articles/s41392-020-0187-x.