Liver and spleen cancers can affect cats and other companion animals. They are more common in dogs than cats but can occur in roughly one percent of cats. It is most common in older, male cats. These tumors can be life-threatening and will require medical treatment.

Liver and spleen cancers occur in the liver, spleen, bile duct, or related tissues. Liver and spleen tumors may be benign or they can metastasize, or spread. Tumors that spread are considered cancerous and can affect other organs. Liver and spleen cancer can occur as tumors within these organs or in blood vessels, as both organs have a high concentration of these.

Cats with cancer of the liver or spleen may not show any symptoms. It is common for symptoms not to occur until the cancer has either spread significantly, ruptured part of the spleen or liver, or entered a late stage. The most common symptoms are similar to those caused by gastrointestinal issues. These cancers can also affect the neurological system as they spread, leading to issues with mental state and behavior. 

Symptoms include:

Various types of benign and metastatic cancers can affect the spleen and liver of cats or other companion animals. The cancer may originate in the spleen or liver, may have occurred in the bloodstream and affected these organs, or might have spread from another part of the body. Types that commonly affect the liver and spleen in cats include:

The exact cause of cancer in the liver or spleen is unknown. Cancers, in general, are caused by an overgrowth of cells, often in a mutated form. A combination of factors is thought to be the cause of cancer throughout the body, including cases that affect the liver and spleen. Certain risk factors make it more likely that a cat will develop cancer in these organs. Both the feline leukemia virus and the feline immunodeficiency virus increase cancer risks. Cancers are also more common in older cats and tend to affect males more frequently than females. It is also possible for liver or spleen cancer to have spread from cancer elsewhere in the animal’s body. 

With symptoms that can closely resemble gastrointestinal issues, your veterinarian may use multiple diagnostic methods to identify what is causing your cat’s condition. Be prepared to discuss your pet’s medical history and any symptoms you have observed. Your veterinarian will perform a full physical examination and may draw blood or collect urine samples for analysis. Standard laboratory testing will be conducted on the blood and urine samples to look for potential causes of your pet’s symptoms. Increases in white blood cell counts, the presence of histamines, or a lack of infection related antibodies may point to cancer. Cancer is most commonly confirmed using x-rays or other imaging techniques. These methods allow your veterinarian to clearly see where the cancer is located and to what extent it has spread. A tissue biopsy may be required if a tumor or mass is located. This biopsy may be obtained by needle or surgical methods depending on the location within the spleen or liver. 

Various treatment methods may be used if liver or spleen cancer is identified. The method may vary related to the location of the tumor and whether the cancer has spread. A combination of treatments may be needed. In some cases, especially if the cancer has spread significantly, treatment may not be an option. Common treatments for liver or spleen cancer include:

Removing the tumor and any associated cancerous cells is the best and most successful method of treating liver and spleen cancer. The liver can withstand a fairly sizeable portion of it being removed if needed. Surgery carries with it some risk and may not be a viable option in all cases, especially if the cat’s health is very poor. Hospitalization will be required if surgery occurs and your pet may need several weeks to recover. 

This is a common cancer treatment, but its use to treat liver and spleen cancer has not been proven. Chemotherapy may be used in conjunction with surgical removal of the tumor, or it may be prescribed if surgery is not an option. Chemotherapy carries a moderate risk, mostly associated with poor health. Your pet may need several chemotherapy treatments. 

Non-steroidal anti-inflammatories are a category of pain reliever that is commonly used to reduce fever, pain, and swelling. They can assist with side effects associated with the cancer and related treatments like surgery. They carry a low risk, but proper dosing is needed to ensure the safety and health of your pet. 

In many cases, other medications will be used in conjunction with other treatments. Antibiotics are often used, especially in cases which tumors have ruptured or caused an infection. Antihistamines are often prescribed with tumors like mast cell tumors, which produce histamine and can cause severe allergic reactions. As with any medication, proper dosing is needed to reduce the risk of side effects. 

Your pet’s prognosis will depend on several factors. In the case of benign tumors or those that can easily be surgically removed, the prognosis is usually good. Inoperable cancers generally have a poor prognosis. Your cat may require a special diet and additional care while recovering from liver or spleen cancer. Be sure to follow all of your veterinarian’s instructions, including those related to medications, nutrition, and follow-up visits. It will be beneficial to your pet to keep their food, water, and litter nearby so they can limit their mobility, especially while recovering from surgery.