Cancer in Hamsters

Hamsters may be "easy" pets, but they are susceptible to cancer. Know the signs and symptoms ahead of time, so you can quickly recognize when something is going wrong. Quicker diagnosis leads to better outcomes, and it isn’t necessarily a death sentence.

Did You Know?
Hamsters can develop melanoma depending on the amount of black pigment on their skin.

Hamsters have a reputation as a “starter pet”, and along with that reputation comes the assumption that they are low-maintenance, easy-to-care, and problem-free pets. However, none of that is true. Their cages require regular cleaning, food bowls and water bottles must be emptied, cleaned, and refilled daily, and the hamster must be kept entertained with a wealth of enriching activities, like chew sticks, tunnels, and toys.

I’m sure you already knew all of that. What you probably didn’t know is that as far as health problems are concerned, barring cancer, hamsters are generally good to go as long as proper sanitation is maintained. Yes, cancer is pretty common in hamsters, especially the kind that cause tumors.

Tumors in Hamsters

The word “tumor” automatically makes people think of cancer and death, but all that the word means is an overgrowth of cells. That’s all a tumor is―a clump of cells dividing out of control, undaunted by the body’s natural control system. Not all tumors are dangerous―malignant tumors are the ones to watch out for, as they spread to other parts of the body and cause major problems in the organs and lymph nodes. But tumors can be benign as well―just lumps that might look weird, but aren’t a hazard to your pet’s health. Benign tumors can cause problems if they grow large enough to limit the hamster’s mobility or affect its quality of life, but once they’re removed, the trouble is over. Luckily, benign tumors are a lot more common than malignant ones in hamsters.

Areas that May Develop Tumors

Among hamsters, the adrenal gland is the most susceptible area for benign tumors to form. On the other hand, malignant cancer may develop internally in the scent gland, organs of the digestive system, lymph glands, intestine, brain, or womb. Older hamsters are more vulnerable to tumor of the lymph glands. Areas where benign tumors may develop are on the belly, ears, above the eyes, or skin.

Signs and Symptoms

If the tumor is on the skin or a slender part of the body, like a leg, you’ll notice it and realize something is wrong. Unfortunately, a tumor on the inside, like the gut or brain, isn’t so apparent, and your hamster can’t tell you he doesn’t feel well. So, you have to look for other signs. If he suddenly starts sleeping all the time, or becomes unexpectedly aggressive, stops eating, or loses weight, it’s a sign that he’s unwell and needs to see the vet. Of course, these symptoms don’t necessarily indicate a tumor, but they do indicate that something is not right―the vet can figure out what that something is. Some hamsters start doing somersaults, walking in circles, and standing on their heads. Such actions are not intended to be playful and are, in fact, indications of neurological problems, such as a brain tumor or stroke. A trip to the vet is definitely in order.

Diagnosis

You cannot tell a benign tumor from a malignant one just by looking, so the vet will diagnose the problem using the tools at his/her disposal. The things you tell him/her about your hamster’s behavior can go a long way toward narrowing down a diagnosis, so tell the vet everything. He/she’ll examine the tumor if it’s visible, and may probably take a biopsy to look at the cells under a microscope. If the tumor’s not visible, blood will be collected to see if your hamster’s body chemistry has been altered in a way that could indicate the presence of cancer. An X-ray may also be called for to see if there’s a tumor hiding somewhere inside.

Treatment

Decide ahead of time how much treatment you can afford, and how much you want to put your pet through. If you’re lucky, the mass will be benign―if it’s small and slow-growing and your hamster is already a few years old, no action may be necessary. Some tumors can be removed completely, and if the cancer hasn’t spread, your hamster could make a full recovery. If the tumor has spread, however, treatment becomes very complicated. The vet will still need to remove the tumor, but it might take radiation therapy and chemotherapy to kill the circulating cancer cells and keep them from infecting healthy cells. In these cases, euthanasia is frequently the most humane option, especially for the hamster. His small body cannot tolerate cancer treatment the way a larger animal could, and his quality of life may be destroyed.

Keep a close eye on your hamster, and examine him regularly. The more you’re used to his daily habits and routines, the sooner you’ll know when something is off. The sooner you get him treated, the better the outcome usually will be.

Disclaimer: This article is for informative purposes only and should not be substituted for the advice of a professional veterinarian.