A brief discussion on the occurrence of Tumors in Rats
By: the Pet Health Care Staff at Pet Care
The two main health problems in pet rats are respiratory
infections and tumors. Female rats, especially, are prone to
both benign and malignant tumors. Happily, most tumors in
rats are benign, encapsulated in a membrane and easy for a
veterinarian to remove surgically.
Malignant tumors (cancer), on the other hand, not only
damage the tissue around them but bits break off and spread
through the rat's bloodstream to start other malignant
tumors. And, because malignant tumors grow into the
surrounding tissue, they usually can't be removed
surgically. The rat usually dies from the damage done to its
internal organs, sometimes before the owner even sees any
sign of illness. If your rat does show symptoms of cancer,
they will be a distended abdomen, bleeding from a lump,
weight loss and lethargy. If your rat is diagnosed with a
malignant tumor, the most humane thing you can do is to have
Benign tumors may grow as quickly as malignant tumors, but
they don't spread to other parts of the rat's body and they
don't do as much damage to the rat. The only way a benign
tumor is likely to kill a rat is if it grows so large that
the rat can't move around well and can't eat enough to feed
the growing tumor and herself. If the tumor isn't removed,
responsible owners have the rat euthanized before she gets
to that sad condition.
It is a good practice to feel all over your rat regularly so
you can find tumors early. The smaller the tumor, the more
easy and low cost will be the surgery to remove it. The most
common tumors in rats are benign mammary tumors. Mammary
tumors may be squishy or firm lumps on the rat's mammary
glands (teats), in their "armpits" or in the belly, and
occasionally they are found in other parts of the animal's
body. If you feel a growth under your rat's skin that can be
moved around slightly, it is almost certainly a benign
As long as the rat is healthy it can have the tumor removed,
even if it is an old rat. If you can't or don't have the
tumor removed, expect to have to euthanize your rat within a
few months as the tumor grows large enough to affect her
life and health. In the meantime, make sure she had the best
food possible and make her life as comfortable as you can.
There are also more rare types of benign tumors in rats,
including pituitary tumors, and they may manifest as loss of
coordination and/or a distinctive posture with the legs held
out stiffly front and back. The only treatment for these
tumors, unfortunately, is also to euthanize the animal.
Some experts believe that feeding a low fat and low calorie
diet to your rats can prevent or lessen the occurrence of
tumors. Obesity and a high fat diet are known to increase
the risk of tumors in both rats and humans.
Making sure that the diet is low in amines and nitrates is
also said to help prevent cancer. Some studies have shown
that vegetables in the crucifer family such as broccoli,
cauliflower and the like have a substance that actually
blocks cancerous tumors from forming, so be sure to include
some of those foods regularly in your pets' diet.
Choose a breeder whose rats have a good record of removing
rats with tumors from their breeding stock. This only helps
a little, since tumors often don't occur until a rat is over
a year old, and by then a breeder has had several litters.
But every little bit helps.
The last suggestion is to keep only male rats as pets, since
they have far fewer tumors than female rats.