My Hamster Has a Tumor: How Long Until She Dies?

Anyone who has had experience with cancer – either with themselves, their loved ones, or their pets – can tell you what a horrible disease it is. Unfortunately, even something as small and cute as a hamster isn’t immune to it, either. Hamsters typically have an average lifespan of two to three years, but a tumor can shorten it.

If your hamster has an inoperable tumor, she typically has about two to three months until she dies. This, however, can vary according to the tumor type, location, your hamster’s age, and how healthy your hamster is despite the tumor. Your vet is better-placed to give you an accurate prognosis.

This article will discuss hamster tumors in-depth and will outline how long a hamster can survive with a tumor. Keep reading to learn more.

Determining if Your Hamster Has a Tumor

One of the telltale signs of a hamster tumor is a lump. Lumps, however, can be due to multiple causes, including tumors, abscesses, injuries, and swollen tissue.

Many hamster tumors occur in the abdominal area, but they can be anywhere in the body.

My Hamster Has a Tumor
My Hamster Has a Tumor

Before assuming that your hamster’s lump is a tumor, it’s worth taking your pet to the vet. After examining your hamster, performing x-rays, and possibly taking a biopsy, your vet will advise you if the lump is a tumor or not.

If you’ve made an appointment to see your vet regarding your hamster’s tumor, below are a few things you can check in the meantime:

  • Tumor location: Lymphoma is a common cancer type in hamsters. It manifests as lumps in the belly and swollen lymph glands in the neck and armpits. Lumps around the mammary glands could be a sign of mammary cancer, while wart-like lumps anywhere on the skin could be due to trichoepitheliomas, skin irritation caused by a virus.
  • Tumor color: Hamster owners often mistakenly believe their hamster has a tumor when it’s an abscess. Hamster abscesses are typically red or dark pink, feel warm when touched, and drain fluid. Abscesses are not cancerous and are due to inflammation or infection.
  • Appetite, thirst, and weight loss: Loss of appetite (and, consequently, weight loss) is a typical sign of a tumor. Increased thirst, however, could indicate an adrenal or thyroid tumor.
  • Tumor growth rate: If you’ve been monitoring the growth rate of the lump on your hamster’s skin and have noticed that it’s growing rapidly, the chances are that it’s a tumor. Hamster tumors usually grow very rapidly, and your vet will need to confirm if it’s malignant or benign.
  • Droppings appearance: Any deviation from your hamster’s regular bowel movements should be investigated. No droppings or droppings that are bloody or loose could indicate an internal tumor.
  • Behavioral changes: If your hamster has been unusually lethargic and hiding away more often, they may be ill or have a tumor. Aggression or biting when being handled could be a sign of pain or sensitivity from a tumor.

Remember that the above information is a guide only and doesn’t replace advice from your vet.

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Types of Hamster Tumors

Tumors are abnormal cell growth in an organ or tissue, resulting in a lump. There are two kinds of hamster tumors:

  • Benign
  • Malignant

We’ll take a look at these tumor types in detail below:

Benign Tumors

Benign tumors are non-cancerous tumors that do not typically cause for concern but should still be evaluated by a vet.

According to Sayers Animal Hospital in Adkins, Texas, benign tumors don’t tend to spread throughout the body and can have a limited impact on your hamster’s health. However, benign tumors can press against nerves or vital organs, causing pain or organ dysfunction. 

Benign hamster tumors will eventually stop growing and can often be left if they’re not causing your hamster pain or distress and do not impact nerves or organs.

Common locations for benign tumors in hamsters include the adrenal gland and the feet.

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Malignant Tumors

Malignant tumors are more concerning as they are cancerous tumors that can metastasize and affect the rest of the body. These tumor types typically grow rapidly, making prompt veterinary care essential.

However, the good news is that only 4% of hamsters develop malignant tumors.

The most common cancers in hamsters are hormone-producing organs, such as the adrenal and thyroid glands.

Malignant lymph gland tumors are also relatively common in hamsters, and the condition is known as lymphoma. The lymphatic system is widespread and extends into the liver, spleen, and lymph nodes, and tumors can be found in any of these locations.

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What Causes Tumors In Hamsters?

Tumors in hamsters can have multiple causes, and your vet is the best person to tell you what has caused your hamster’s tumor. The main reasons include the following:

  • Genetics
  • Diet
  • Environment
  • Age
  • Sex


Although tumors are common in all hamsters, some breeds are more prone to developing tumors due to a genetic disposition.

Teddy Bear and Dwarf hamsters are more sensitive to disease and tumors than golden hamsters.

Scent gland tumors are common in Syrian and Dwarf hamsters. If your hamster is one of these varieties, it’s worth monitoring the scent glands’ appearance (they’re located in the mid-belly area). Any change in color or size should be investigated as a potential tumor.


Feeding your hamster an unhealthy diet can have short and long-term consequences. One of these is increasing your hamster’s risk of developing a tumor.

Regularly feeding your hamster food that lacks nutrition with a high sugar content can put her at risk for developing a tumor.

You can help prevent tumors by feeding your hamster ASPCA-approved hamster food with a suitable vitamin and mineral content to keep your its immune system functioning optimally.

Avoid feeding your hamster muesli-type hamster food mixes as your hamster will eat the sugar-rich ingredients and leave the healthy bits, resulting in weight gain (which can predispose them to cancer and diabetes).

Hamsters love Timothy hay, which has the benefit of being fiber-rich to promote healthy digestion. 

It’s tempting to feed your hamster inexpensive, tasty, and highly processed treats, but these can also increase the tumor risk as they’re high in calories with little nutritional value. Opt for small amounts of fresh vegetables and the occasional boiled egg instead.

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Exposure to environmental stressors and toxins can make your hamster more prone to developing tumors.

In the wild, hamsters live in warm and dry climates. If your hamster’s cage is in a cold and draughty place (close to an air conditioning unit, for example), they can become unhappy and depressed.

Hamsters enjoy predictable light conditions as the routine promotes a feeling of safety. They’re also sensitive to bright light and become stressed if they’re continuously exposed to bright and unnatural light.

Other things that can make hamsters feel stressed include loud noises and ultrasound waves. Vacuum cleaners and televisions can be too loud for hamsters, and they’re also sensitive to ultrasonic waves that can emanate from computer screens or cell phones.

Stress and depression in hamsters can lead to elevated cortisol levels, eventually leading to tumor development.

Exposure to toxic substances, such as paint, cleaning products, or glue fumes can also promote tumor development in hamsters.


As with most animals, the older your hamster is, the more likely she is to develop a tumor.

Young hamsters, however, can still develop tumors.

Hamsters have a two to three-year lifespan, and when they reach one year old, they’re considered geriatric.

If your hamster is older than a year, she’s, therefore, at a greater risk of developing tumors.

It’s worthwhile gently checking for lumps in your geriatric hamster when you play with her. Some tumors aren’t visible externally, and gently running your finger along your hamster’s abdomen, and back is an excellent way to screen for tumors.


Your hamster’s sex can make them more at risk for malignant tumors.

Female hamsters are more prone to cancerous tumors as many cancers in hamsters involve the female reproductive system.

Male hamsters, however, can develop tumors on the testicles.

My Hamster Has a Tumor How Long Until She Dies
My Hamster Has a Tumor How Long Until She Dies

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Are Hamster Tumors Painful?

If you own a hamster, you probably care deeply about her and don’t want her to be in pain.

Hamster tumors may be painful, but it’s not easy to tell if your hamster is in pain. However, if she has difficulty moving around, isn’t performing her usual daily routine, is not eating, doesn’t enjoy being handled, or is sleeping excessively, she may be in pain.

In such cases, it’s best to consult your vet for pain relief.

Pain relief medications for hamsters are typically only available with a prescription from your vet, as it’s crucial to get the medication type and dosage correct. 

It’s not a good idea to give hamsters other pets’ medication as it may harm or kill them.

How Are Hamster Tumors Treated?

Once your vet has confirmed that your hamster has a tumor, you’ll want to know how it can be treated.

Hamster tumors are treated surgically, as long as the tumor is close to the skin and not too large. Internal tumors are more challenging to remove as they may be inaccessible and close to vital organs. Surgery for internal tumors can be expensive, complicated, and not worth the risk. 

Before suggesting surgery, your vet will weigh the pros and cons of operating on such a tiny animal. Your vet needs to be confident that your hamster will survive the anesthesia and the blood loss from the surgery.

Hamsters are not typically given chemotherapy or radiation treatment to remove or shrink tumors. However, your vet may prescribe steroids to slow the growth or shrink inoperable, benign tumors.

If your vet has determined that your hamster’s tumor has metastasized (spread to the rest of the body), they may suggest palliative care. This allows your hamster to remain comfortable and enjoy a better quality of life.

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After your vet has confirmed that your hamster has a tumor, they can advise you of your hamster’s prognosis.

Malignant hamster tumors or benign tumors that can’t be removed can give your hamster an expected remaining lifespan of around two to three months. Malignant tumors will spread cancer to the rest of the body, while benign tumors can impact major organs.

You increase the chances of a good prognosis for your hamster the sooner you seek veterinary treatment. Some tumors become too large and risky to remove via surgery if left too long.

If your vet has confirmed that your hamster’s tumor is untreatable, the best thing you can do is to keep her as comfortable as possible.

A few ways to keep your hamster comfortable are as follows:

  • Pain-relieving medicine. Chat to your vet about hamster-specific pain relief or provide a small hot water bottle to relieve localized pain. 
  • Plenty of food, water, and treats. If you’ve been told that your hamster only has a short time left, it’s worth feeding her favorite foods and treats to keep her as happy as possible. You should also include plenty of clean and fresh water.
  • Limiting the handling of your hamster. Your hamster’s tumor may make handling them painful or sensitive, so you may consider restricting handling only when necessary.
  • Creating a peaceful living environment. As sensitive animals, hamsters don’t enjoy loud noises and bright lights. Ensure that your hamster’s cage is in a warm, dry and comfortable location.
  • Consulting your vet when problematic symptoms arise. Hamster tumors can affect various body functions and can cause unpleasant symptoms. If you notice new symptoms, chat to your vet for advice as they may suggest treatments, such as anti-diarrheal or antibiotic medication if your hamster has a bacterial infection.

If your vet believes that your hamster is in a lot of pain or their quality of life is very poor, they may suggest euthanasia. Although it’s painful to think about this humane option, it’s worth preparing yourself and putting your hamster’s comfort first.

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Hamster lumps aren’t always tumors, and your vet needs to confirm the diagnosis. If your hamster has a tumor, it can be benign or malignant.

Depending on where the tumor is located, your vet might be able to remove it surgically. Otherwise, they may suggest comfort treatment only.

If your hamster has an untreatable tumor, she typically has around two to three months left to live. This is a guideline only, and factors like age, general health, and tumor growth rate can affect it.