Copyright 2007 Pet Meds Online.Org
Cancer In Dogs
Cancer In Dogs:
A cancer
is a growth which is beyond the body's control. Few words evoke
such fear as cancer. We should bear in mind many cancers are
treatable and some do not even require treatment. Although cancer
can be a serious or fatal condition it is not an inevitable death sentence.
If My Dog Has A Benign Tumor, Should It Be Removed?
The vet will decide each case on its own merits. The position of
the tumor must be considered. A growth on an elbow or eyelid
could worry a dog even though it is not life threatening. Benign
tumors may be knocked, or ulcerate, bleed or otherwise cause
inconvenience and the vet may recommend removal for these reasons.
Lipoma (Fat Tumor) In Dogs
Lipomas are very common, especially in older dogs and in
Labradors, Terriers, and overweight dogs. They are composed of
fat tissue and grow very slowly. They are usually found just
under the skin. They feel soft, have smooth borders and, as they are
not very firmly attached, can usually be moved around under the
skin. Lipomas are usually small, varying from a tiny size to a
few centimeters in diameter. Occasionally lipomas become very
large and "melon" sized.
Breast Tumors (Mammary Tumors) In Dogs
Breast tumors account for over half the total number of tumors
in bitches. Mammary tumors are much more common in bitches over 6
years of age, especially if they have not had any litters, and are rare
in bitches that have been spayed before they are 2 years of age.
After 2 years, spaying appears to make little difference to the
incidence of breast cancer. Males are rarely affected.
Malignant Tumor
A cancer grows out from its borders, invading and destroying
surrounding tissues. Cancerous cells may break away from the
parent tumor and take root some distance away. Such tumors are
termed "secondaries" (the parent tumor being called the "primary").
The Treatment Of Malignant Growths
If a malignant tumor is suspected it should be removed at the
earliest opportunity. This is not always possible: the tumor may
already have spread, either branching out locally or by seeding tumor
cells to other parts of the body ("secondaries").
As an alternative to surgery, new treatment methods are being
developed. The use of x-rays to destroy malignant cells is very
effective in some cases but in veterinary medicine this form is not
always available. Sometimes radioactive needles are inserted into
a tumor. The radioactivity emitted is capable of destroying some
tumors without affecting surrounding healthy tissues. Drug
treatment (or "chemotherapy") is still relatively new, but effective
and safe drugs to control cancers may soon be developed.
How Can We Tell The Difference Between A Benign Growth And Malignant Tumor?
Some types of tumors are fairly easily recognized and the vet
can give you a confident assessment of their usual course and likely
dangers. But no matter how "typical" a tumor appears to be, the
final diagnosis can only be made by a pathologist. By studying
the microscopic structure of a tumor, pathologists determine how it
will behave and whether it is likely to recur after removal. Many
tumors are not easily classified as benign or malignant but lie
somewhere between.
Common Characteristics Of Benign vs Malignant Skin Tumors:
This chart is a guide only. Tumors can be deceptive and do not always follow the rules.
| Rate Of Growth: |
Slow |
Usually Fast |
| Shape: |
Regularly shaped, often rounded or oval with well-defined borders. |
Irregular in shape, often hard to determine where the growth finishes. |
| Pain: |
Often does not worry the dog at all - but it depends on the position of the tumor. |
Often inflamed - area may be swollen, painful. Varies with the stage of the growth of the tumor. |
| Other Features: |
Often can be moved slightly. |
Held firm to surrounding tissues. |
Benign Tumor
Malignant Tumor
If My Dog Has A Malignant Tumor, What Should I Do?
If a malignant tumor is suspected, the situation is serious.
Some malignant tumors spread very quickly. If the tumor has
already spread, for example, to the lungs or liver, it is pointless to
operate. Euthanasia offers a comfortable release from a cancer
which has spread. A malignant tumor may be so large and extensive
that it is impossible or extremely difficult to remove, e.g. tumors of
bone, liver, lung or pancreas, however malignant tumors involving the
skin can often be completely removed, so the prognosis for a successful
outcome can be good.
Benign Tumor:
One that grows by expanding or swelling from within somewhat like a
balloon being blown up. A benign tumor is usually surrounded by a
capsule.
These
tumors are felt first as irregularly shaped, firm masses within the
mammary glands. An observant owner may discover them when they
are only pea-sized and smaller. If neglected, the can become very
large and some types spread to involve many or all of the bitch's 5
sets of mammary glands.
Early detection of breast cancer means that if surgery is needed, it is less extensive and more likely to be successful.