Tumors and Cancers in Hamsters

Teresa Manucy, DVM
By Teresa Manucy, DVM on May 5, 2022
Little hamster and face mask on blue background stock photo

In This Article


What Are Tumors and Cancers in Hamsters?

A tumor is defined as a swelling in any part of the body caused by the abnormal growth of tissues or cells. In hamsters, tumors that are limited to a single organ or area of the body are usually described as benign. These tumors do not spread to other locations and may even be surgically removed. Malignant tumors develop in one location and spread into other parts of the body and are considered cancerous.

Hamsters often experience tumors in their adrenal glands, reproductive organs, digestive tract, kidneys, and especially skin. Tumors in the adrenal glands and reproductive organs are often benign, but still have health-related symptoms. Skin tumors are commonly cancerous.

Hamsters can also get lymphoma, a cancer of the immune system. Dwarf hamsters are more likely to develop tumors than Syrian hamsters.

Symptoms of Tumors and Cancers in Hamsters

Symptoms associated with tumors in hamsters include:

  • Visible skin growths

  • Depression

  • Decreased appetite

  • Diarrhea (sometimes with blood)

  • Weight loss

  • Abdominal pain

  • Hair loss

  • Increased thirst

  • Overgrooming

  • Weakness, or altered gait

Causes of Tumors and Cancers in Hamsters

A combination of inherited genetic factors along with various environmental factors will influence the development of tumors in hamsters. The most common benign tumors occur in the thyroid and adrenal glands. Although these are usually benign, these tumors can cause overproduction of hormones, which results in symptoms.

The most common site for malignant cancer in hamsters is the skin. Up to 90% of cancers observed in hamsters occur in the skin.

How Veterinarians Diagnose Tumors and Cancers in Hamsters

The first step in determining a diagnosis of tumors and whether or not they are cancerous is to have the pet examined by a veterinarian. The vet will visually examine the hamster and note any physical abnormalities. If they see something unusual, they may follow up with further testing.

A common test used to diagnose cancer is called a fine needle aspiration. This test is a type of biopsy that is performed with a small needle and a syringe. In this test, the needle is carefully guided into the tumor and small sample of cells is withdrawn into the syringe. This sample is then directly placed onto a microscope slide to be examined. If this test does not determine an answer from the small sample size, then a biopsy may be necessary.

A biopsy is a type of test used to diagnose cancer. During a biopsy, a larger tissue sample is taken surgically while the pet is under anesthesia. If the tumor is small enough, the entire tumor may be removed during the biopsy. The tissue sample is then processed by a laboratory and viewed by a specially trained veterinarian.

Treatment of Tumors and Cancers in Hamsters

If a diagnosis of cancer is confirmed, then a treatment recommendation may be given based on the type, stage, and location of the tumor involved. A solitary skin cancer may be surgically removed if it’s not too large or impacting vital structures on the body. Surgical removal may help prevent tumor spread when performed early in the diagnosis.

If the tumor can’t be removed, alternative treatments such as chemotherapy or radiotherapy may be used. Chemotherapy is the use of medications that kill cancer cells by interrupting the dividing and reproducing cells in the body. The use of radiation to kill cancer cells is another therapeutic option. Your veterinarian will discuss whether these options are available for such a small patient, as well as the expected survival rates and potential side effects of these therapies before treatments are selected.

Recovery and Management of Tumors and Cancers in Hamsters

The timeline of recovery after tumor and cancer treatments depends on the type of the cancer and the treatment selected. Skin cancers are easily removed, and a full recovery can be expected after two weeks of incision healing time. Malignant tumors affecting multiple organs may require several rounds of chemotherapy. Due to the lasting effects of chemotherapy on both healthy and diseased cells, it can take months to recover after treatment. Radiation is also damaging to normal and abnormal tissues and usually requires weeks for recovery.

Certain cancer treatments may also affect how hamsters are able to function in their daily lives. Their diet may be altered to address a poor appetite, which may include syringe feeding with a critical care supplement. Your hamster’s exercise may also be restricted since they can’t be as active while incisions heal from removal.

If a tumor is not able to be completely removed, there is always the chance that it may grow back. This risk of recurrence is one of the reasons why owners choose not to pursue advanced treatments for hamsters.

Tumors and Cancers in Hamsters FAQs

How do I know if my hamster has cancer?

A veterinary evaluation is needed to determine a diagnosis of cancer in hamsters. If cancer is suspected on physical examination, a biopsy or fine needle aspiration may be required. For internal tumors that cannot be visualized or sampled, an x-ray and/or ultrasound may be necessary.

Can hamsters survive tumors?

Benign tumors are very survivable as these do not cause disruption of organ functions. Malignant tumors are more likely to shorten the quality and quantity of life. Cancerous tumors may spread or become enlarged and interfere with normal activity with or without treatment.

Can hamster tumors be cured?

The complete surgical removal of a solitary growth is the cure for tumors in hamsters. Depending on the type of tumor, the risk of spread to other tissues will vary. Each hamster owner will be challenged to determine the best course of action when facing a tumor diagnosis.

Featured Image: iStock.com/Natalia Kopyltsova

Teresa Manucy, DVM


Teresa Manucy, DVM


Dr. Teresa Manucy is a 1997 graduate of the University of Florida College of Veterinary Medicine. She completed an internship in small...

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