Cancers and Tumors in Guinea Pigs

Benign and Malignant Tumors in Guinea Pigs

Tumors are the result of an abnormal multiplication of body cells, resulting in a growth, or lump of tissue, which may be benign (harmless) or malignant (spreading and dangerous).

Most types of cancer are not common in guinea pigs until they are four to five years old. After that age, between one-sixth and one-third of guinea pigs are known to develop a tumor. Guinea pigs that have been inter-bred (within relatives) are more prone to tumor and cancer development.

Treatment, if recommended, will depend on the type and location of the tumor or cancer. While the outcome for benign skin tumors is generally good, the general outcome for some cancers of the blood is poor and affected guinea pigs often live for only a few weeks after diagnosis.

Symptoms and Types

Lymphosarcoma, a malignant tumor of the lymphatic tissues, is the most common tumor in guinea pigs. It causes what is referred to as Cavian leukemia. Signs may include a scruffy hair coat and occasionally masses in the chest area and/or an enlarged liver or spleen.

As far as benign skin tumors, trichoepitheliomas are some of the most common occuring in guinea pigs, especially younger guinea pigs, often forming at the base of the tail. Younger guinea pigs may also develop skin tumors or leukemia, which is cancer of blood cells.



Tumors are caused by an abnormal multiplication of body cells. Certain guinea pigs are genetically predisposed to this abnormality.


You will need to give a thorough history of your guinea pig's health and onset of symptoms, along with as much family history as you have available to you.

Based on the location, some tumors are more easily diagnosed when the growths can be seen and palpated (examined by touch) externally. When the tumor or cancer is present in the internal organs, it will need to be diagnosed by X-rays or scans. A complete blood profile will be conducted, including a chemical blood profile, a complete blood count, and a urinalysis. A diagnosis can then be confirmed by the blood count and and an examination of fluids from the lymph nodes or chest cavity in cases of leukemia and lymphosarcoma.

  Next >