Tumors in Hamsters: Causes, Symptoms & Treatment

Tumors are swellings that can form in any part of the body as a result of abnormal growth of cells or tissues. Tumors in hamsters can develop in the adrenal glands, digestive tract, reproductive organs, thyroid glands, kidneys, skin, and lymph nodes.

Tumors limited to one part or organ (do not spread to other parts or organs) are described as benign. Benign tumors can be surgically removed if located in an accessible location. In contrast, malignant tumors can spread to other parts of the body or organs and are cancerous.

Benign tumors mainly affect the adrenal glands, thyroid glands, and reproductive organs and often cause the overproduction of hormones. On the other hand, the most common malignant tumors in hamsters are nodal lymphosarcomas, cancer of the adrenal glands, and uterine adenocarcinomas.

Malignant tumors in hamsters have high mortality rates due to their high metabolic rates, which play a big role in speeding the growth of tumors in other parts or organs.

tumors in hamsters

Symptoms of tumors in hamsters

Benign tumors are quite detectable especially when they form under the skin. The challenge is when the lumps are in hidden parts such as armpits. It can take time before you notice the symptoms because there are no other noticeable early symptoms apart from suspicious lumps.

That said, you should consult your vet immediately if you notice any of these symptoms:

  • Visible lump-like skin growths
  • Decreased appetite
  • Weight loss or gain
  • Abdominal pains
  • Abnormal hair loss
  • Increased thirst
  • Altered gait
  • Poor or lack of grooming

Causes of tumors in hamsters

The causes of tumors in hamsters range from genetic to environmental factors. In terms of genetic predisposition, Syrian hamsters are more susceptible to developing tumors than Dwarf hamsters.

Environmental factors include exposure to things such as nicotine and hyperoxia (oxygen toxicity), which studies have proven to increase the chances of tumors growing.

Diagnosis of tumors in hamsters

Physical examination is used to determine the physical symptoms of tumors in hamsters. The veterinarian will look for lumps on the skin and in parts such as under the armpits and inside the mouth.

If the vet determines the tumors to be malignant (cancerous), they will conduct further tests. Fine needle aspiration is the most common procedure used to diagnose cancer in hamsters. The vet will carefully insert a fine needle into the tumor to draw a small sample of the cells for analysis.

In case the analysis of the sample cells does not yield conclusive results, a biopsy will be used. A larger sample of the affected cells will be taken surgically and then studied for a conclusive diagnosis.

Treatment for tumors in hamsters

The right treatment will depend on the type, location, and stage of the tumor. A localized tumor may be surgically removed if it is small and/or is not close to vital organs. This procedure is most effective with benign tumors because they do not spread to other parts or organs.

In case the tumor cannot be removed through surgery, chemotherapy and/or radiotherapy can be used as alternative treatments. These options kill cancer cells and prevent them from further dividing and reproducing.

Point to note: Surgery may not be ideal in some cases because hamsters are small pets and surgery carries high risks.

Recovery from tumor treatment

The recovery timeline largely depends on the treatment used and how advanced the tumor was. Recovery from skin tumors is about two weeks while malignant tumors that affect multiple organs may need multiple rounds of chemotherapy. The lasting effects of chemotherapy mean it can take months for the hamster to fully recover.

Some cancer treatments may affect the hamster’s daily life and the kind of activities it can engage in. Diet may also be affected and you may need to syringe-feed your pet if it cannot eat normally. A tumor can also reoccur if it is not removed completely, which means the hamster may never achieve full recovery.


Let’s have a look at a few of the common questions about tumors in hamsters.

a). Can hamsters survive tumors?

Yes, hamsters can survive benign tumors because they are easy to treat and manage. Unfortunately, malignant tumors have higher mortality rates, especially in the event of late diagnosis. Take immediate action to visit a veterinarian if you notice any suspicious lumps or if you suspect your hamster has a tumor.

b). What causes tumors in hamsters?

The causes of tumors in hamsters can be genetic or environmental. Certain hamster breeds, including Syrian hamsters, are more susceptible to developing hamsters. Exposure to things such as nicotine and too much oxygen can also increase the chances of a hamster getting tumors.

c). Are hamster tumors contagious?

Some tumors, such as reticulum cell sarcoma, can spread from one hamster to another. Gnawing at tumors and cannibalism are two common modes of transmission between hamsters.

Final thoughts

Tumors are common in hamsters but can be managed and treated if caught early. Surgical procedures and the use of chemotherapy and radiotherapy are the most effective treatment options. We recommend getting in touch with your vet in case you notice any suspicious lumps or any of the symptoms noted above.