There is a wealth of information on the internet about cancer in pets. Below is an overview of the different types of cancer and treatment options available. To be clear, the information on this site is meant to take some of the mystery out of cancer in pets. It is not meant to be a diagnosis or treatment plan for your pet.

The type of treatment ("protocol") best for your pet will be determined by a number of factors. Your veterinarian or the doctors and staff of MedVet Oncology will be able to answer your questions regarding cancer and treatment options for your pet. 

All of the information provided below is from the National Canine Cancer Foundation website: www.wearethecure.org. Copyright 2006.

What is Cancer?
Cancer is an uncontrolled growth of abnormal cells on or within the body. Cancer may be benign or malignant. It may be localized or it may invade adjacent tissue and spread throughout the body.

How Common is Cancer?
Cancer is common in pet animals and the incidence increases with age. Cancer accounts for almost half of the deaths of pets over 10 years of age. Dogs get cancer at roughly the same rate as humans, while cats get fewer cancers.

How is it Diagnosed?
Strong circumstantial evidence of cancer can be attained from x-rays, blood tests, ultrasonography, the pet's physical examination and medical history. Most cancers, however, will require a biopsy (a removal of a piece of tissue) for confirmation that cancer exists and to grade the level of severity from benign to aggressively malignant.

Is Cancer Preventable?
Unfortunately, the cause of most cancers is not known and, therefore, prevention is difficult. Early detection and treatment are the best ways to manage cancer in pets.

What Type of Cancer did Chippy Have?

Chippy had Lymphoma. Below is more information about this cancer.

Lymphoma - Lymphoma is one of the most common cancers seen in dogs. In fact, we estimate that lymphoma occurs about 2 to 5 times as frequently in dogs than in people. Although there are breeds that appear to be at increased risk for this disease, lymphoma can affect any dog of any breed at any age. It accounts for approximately 20% of all canine tumors, and less than 80% of cancers originating from blood cells.

Most of the time, lymphoma appears as “swollen glands” (lymph nodes) that can be seen or felt under the neck, in front of the shoulders, or behind the knee. Occasionally, lymphoma can affect lymph nodes that are not visible or palpable from outside the body, such as those inside the chest or in the abdomen. In these cases, dogs may accumulate fluid in the chest that makes breathing difficult, or they may have digestive problems (diarrhea, vomiting, or painful abdomen). If left untreated, dogs with lymphoma will generally succumb to the disease within 3 to 4 weeks.

Treatment with prednisone (a corticosteroid) alone generally can induce short-lived remissions (usually less than 8 to 12 weeks), but frequently renders the disease resistant to further treatment. Durable remissions are achievable in lymphoma, so the disease is considered “treatable.”

Multi-agent chemotherapy consisting of L-asparaginase, vincristine, cyclophosphamide, doxorubicin, and prednisone, which is the standard-of-care for this disease, will induce remissions of 12 to 18 months in many cases. However, there are various subtypes of lymphoma that exhibit different behaviors, and some of the more aggressive types are unresponsive to any available treatment.

10 Early Warning Signs of Possible Cancer

1. Abnormal swellings that persist or continue to grow
2. Sores that do not heal
3. Weight loss
4. Loss of appetite
5. Bleeding or discharge from any body opening
6. Offensive odor
7. Difficulty eating or swallowing
8. Hesitation to exercise or loss of stamina
9. Persistent lameness or stiffness
10. Difficulty breathing, urinating, or defecation

Osteosarcoma
Osteosarcoma is the most common type of primary bone cancer in dogs accounting for up to 85% of tumors that originate in the skeletal system. It is estimated that at least 6,000 new cases, and perhaps even more than 8,000, are diagnosed in dogs each year in the United States.

Although it is mostly a disease of older large or giant breed dogs, it can affect dogs of any size or age. Osteosarcoma may be found in many areas, but it most commonly affects the bones bordering the shoulder, wrist and knee.

The first sign an owner usually sees with this disease is lameness in the affected leg. They may also notice a swelling over the area or their dog may seem painful at the site. Most of the time osteosarcomas and other bone tumors are found when their veterinarian takes a radiograph (“x-rays”) of the affected limb. A careful physical exam, blood work and urinalysis is also important to assess the overall health of your dog.

Melanoma
Melanoma occurs commonly in dogs with pigmented (dark) skin. Melanomas arise from pigment producing cells called melanocytes, which are responsible for coloring the skin. Any dog can be affected, but Gordon Setters, Standard and Miniature Schnauzers, Doberman Pinschers, and Scottish terriers, among others, are at increased risk to develop melanoma, suggesting that this disease may have a hereditary component.

Melanomas can occur in areas of haired skin, where they usually form small, dark (brown to black) lumps, but can also appear as large, flat, wrinkled masses. Melanoma of the haired skin in dogs is usually a benign tumor, although it can cause severe discomfort. In contrast, malignant melanoma, which develops in the mouth or in the distal limbs (usually the toenail beds), is an incurable disease. These tumors have very often spread to distant parts of the body (metastasized) by the time they are first noticed, making complete surgical removal impossible.

Hemangiosarcoma
Canine hemangiosarcoma is an incurable tumor of cells that line blood vessels (endothelial cells). Based on current estimates of the lifetime risk of cancer in dogs and the prevalence of hemangiosarcoma, we predict that of the 73.9 million pet dogs living in the United States today, as many as two million may get this cancer and die from it. Although dogs of any age and breed are susceptible to hemangiosarcoma, it occurs more commonly in dogs beyond middle age, and in breeds such as Golden Retrievers, German Shepherd Dogs, Portuguese Water Dogs, and Skye Terriers, among others.

Hemangiosarcoma is extremely indolent – that is, it develops slowly and is essentially painless – so clinical signs are usually not evident until the advanced stages when the tumors are resistant to most treatments. Less than 50% of dogs treated with standard-of-care of care for this tumor (surgery and intensive chemotherapy) survive more than six months.

Canine Squamous Cell Carcinomas
Squamous cell carcinoma is one of the most common cancers found in dogs. Common sites are the mouth and the toes (nailbeds). Early detection and complete surgical removal is the treatment of choice and fewer than 20% develop metastatic disease. SCC of the tonsil and tongue are quite aggressive and fewer than 10% survive 1 year or longer despite treatment measures.

Cancer Treatment in Pets

What Causes Cancer in Dogs?
We know the cause of very few cancers in companion animals. The development of cancer can occur in any organism from excessive exposure to carcinogenic agents such as certain chemicals, UV or X-irradiation and from some viral infections. Although we do not know the exact cause for each type of cancer in pets, the underlying problem is due to abnormal genes that result in uncontrolled growth of cells, which may invade into surrounding tissues or spread to other areas. The number of cancers that are actually heritable (capable of being passed on to offspring) is unknown in dogs but it has been occasionally documented.

How is Cancer Treated?
Each type of cancer requires individual care and may include a combination of treatment therapies such as surgery, chemotherapy, radiation, cryosurgery (freezing), hyperthermia (heating) or immunotherapy. Once you have a diagnosis, your veterinarian will discuss the best treatment option(s) for your pet. In some instances, your veterinarian may refer you to a board-certified oncologist (cancer specialist) depending upon the recommended course of treatment.

Treatment Strategies.
Cancer specialists use a team approach to detect and treat complex cancers. Depending on your pet’s diagnosis, the cancer specialist will consult with other specialists, who may include surgeons, medical oncologists, diagnostic radiologists, radiation oncologists and other professionals who have been trained in treating cancer.

Whether your pet receives radiation therapy, chemotherapy, surgery or a combination of therapies, a customized treatment plan should be designed to most benefit your pet and suit your needs.

Diagnosis and Staging.
Your pet's general health status is assessed to identify disease which may adversely affect prognosis, and limit or alter therapy. After a thorough physical examination the screening laboratory evaluation generally includes a complete blood cell count, serum biochemistry panel, and urinalysis. Other general diagnostic tests are performed as indicated.

Deciding on Treatment Options.
The decision making process for management of cancer in pets can be a complicated and difficult process. The evaluation of the general health of the patient, the type of cancer, access to specialized treatments and the emotional, time and financial commitment to conduct the treatment must be carefully considered. The benefits, risks and costs cannot be adequately determined without some assistance and support. Such support is best obtained from family, friends and veterinary professionals.

Goals of Treatment.
Maintaining the highest quality of life for the longest period of time is always the goal of cancer management in companion animals. This goal must be considered within the context of emotional and financial factors. Decisions are often difficult.

The best service that can be provided is a knowledgeable, unbiased assessment of the condition and a frank discussion of options sufficient to permit an informed decision. This may involve consultation or referral to a specialist or a comprehensive cancer center. Curative therapy is designed to attempt permanent control of the tumor using aggressive but not excessively debilitating treatments. Multiple treatment modalities are often employed.

All of the information provided on this page is from the National Canine Cancer Foundation website: www.wearethecure.org. Copyright 2006.