What is Cancer?

Cancer is a group of diseases in which abnormal cells within the tissues of the body grow without control.  The abnormal cells can invade surrounding tissues, ultimately spreading to other organs throughout the body.  There are more than a hundred specific cancer types, each showing unique behaviors and requiring tumor specific treatment strategies.

In a normal body, new cells (which form the structures of the body and control its functions) are constantly being made to replace old or damaged cells.  This process (cell multiplication and cell death) is very well regulated so that the right number of cells is maintained within the tissue or structure.  When this process goes wrong and the body begins to produce more cells than it needs and/or cells don’t die when they should, the extra cells may undergo genetic changes, and can then form a mass called a tumor.

How is cancer diagnosed?

During a physical examination of a pet, a veterinarian inspects and palpates or feels many anatomic structures and tissues of the body.  If an area is determined to look or feel abnormal, a tumor may be considered as one of the possibile causes.  Additionally, abnormalities found in blood test results or radiographs (x-rays) taken of sick pets may lead the veterinarian to suspect that a pet has a tumor or cancer.

If an abnormality is identified or suspected, pets typically require a series of tests to determine if it is cancer (or another disease), which type of cancer, where the cancer is located, how fast it is growing, and the malignancy of the tumor. Cancer staging is an important part of helping a veterinarian guide pet owners in treatment options and giving a prognosis for the pet.

Benign vs. malignant tumors

Tumors are described as either benign (noncancerous) or malignant (cancerous).  Benign tumors typically remain localized to one place and do not invade surrounding tissues or distant organs.  They are not usually dangerous but can cause medical problems once their size begins to compress surrounding tissues.  In contrast, malignant tumors contain cells that have the ability to invade neighboring tissues and spread to distant organs via blood circulation or the lymphatic system, a process known as metastasis.

Is cancer treatable?

Cancer has become the number one cause of death in older cats and dogs.  It accounts for about 50% of pet deaths per year.  Though cancer takes many lives, it is for the most part a treatable disease, comparable to diseases like heart failure or kidney failure.

There have been many advances in the treatment of cancer that can provide owners alternatives for giving their pets a high quality of life for years to come.  Treatment recommendations for pets with cancer depend on the type of cancer identified.  Options may include chemotherapy, radiation therapy, and/or surgery (or combinations of these various treatments).

Advances in the detection and treatments of cancer for both pets and humans are significant, but early diagnosis is important in order to have better outcomes to treatments.


What About Cancer Prevention?