Cancer is the number one natural cause of death in geriatric cats and dogs, and it accounts for nearly 50 percent of deaths each year. Although cancer is the leading cause of death, it’s also the most treatable disease when compared with congestive heart failure, renal failure, or other debilitating diseases.
Cancer is a broad term used to describe cells within the body that are growing and dividing in an abnormal manner and rate. Healthy cells go through a cycle in which they grow and divide as the body needs new cells. Abnormal cells grow and divide at uncontrolled rates, often forming tumors or masses. These growths can be either benign (non-cancerous) or malignant (cancerous). In some cases, the cancer cells do not form growths; instead they affect the blood, which circulates abnormal cells throughout the body. To the medical professional, cancer is a word used to describe a condition of uncontrolled growth. We’ve studied it, categorized it, and classified it by any number of criteria. Very few words, however, create more fear in the imagination of people. Most people’s perception of cancer, surgery, and chemotherapy is colored with fear and hopelessness. However, with the development of sophisticated treatments and the willingness of pet owners to pursue those options, cancer is claiming fewer four-legged victims these days. Successful treatment of pet cancer depends on early detection. Knowing the signs of cancer in your pet is key:
Abnormal swellings that persist or continue to grow
Sores that do not heal
Loss of appetite
Bleeding or discharge from any body opening
Difficulty eating or swallowing
Hesitation to exercise or loss of stamina
Persistent lameness or stiffness
Difficulty breathing, urinating, or defecating
Though pets of any age can develop cancer, it is generally more common in adult and older animals. Also, certain breeds of dogs and cats have a higher incidence of some types of cancers. Talk to your veterinarian about risk factors that may affect your pet. Early detection of pet cancer is critical for successful treatment and recovery.
Cancer diagnosis starts with an initial physical examination and discussion about the symptoms you've identified. Sometimes your vet will see a tumor on your pet's skin or in his mouth, or feel a tumor in your pet's abdomen - if this is the case further tests will need to be performed to identify the nature of the tumor.If nothing is found on a physical examination, additional tests can be done to rule out the presence of a tumor.
1. Imaging - Radiographs (x-rays) of tumors can help to reveal the extent and location of a tumor, and also are useful to evaluate the spread of cancer in the body. An abdominal ultrasound examination enables your vet to look at your pet's internal organs to identify the presence of any tumors. CT or CAT (Computed Axial Tomographic) or MRI (Magnetic Resonance Imaging) scans give much more detailed results than either x-rays or ultrasound examinations. They can make the diagnosis that much more accurate, and may remove the need for further invasive tests to determine the nature of any tumor that's present. CT and MRI scans are usually only available at specialty veterinary hospitals or referral centers, and are expensive procedures. Both procedures will require your pet to be anesthetized since any movement they make while the scan is taking place will result in the images being unreadable.
2. Cytology is the examination of cells taken (aspirated) from your pet's body with a needle, basically a vaccination in reverse. Cytology can be an accurate diagnosis method, but it does have its limitations - not all tumors will give up their cells when a sample is taken, and sometimes only blood is taken. While cytology can diagnose malignant tumors, it can't eliminate the presence of cancer when only blood has been taken in the sample.
3. Surgical biopsy is the most certain way to diagnose cancer in your pet. The procedure involves the removal of tissue which is then examined under a microscope. Your pet may have an incisional biopsy, where only a small part of the tumor is removed, or an excisional biopsy, where the whole tumor and surrounding normal tissue is removed. Which type of biopsy you pet will have will depend upon how big the tumor is and where it is located.
My pet has been diagnosed with cancer, now what?
There are many decisions to be made when a pet is suspected of having cancer or has been diagnosed with cancer. Some of the treatment options are outlined below.
Surgery is the oldest form of cancer therapy and has been responsible for the cure of more patients than any other treatment. This great success is mainly due, in part, to the development of new surgical techniques, but could not have happened without similar advancements in anesthesia, pain control, and critical care support. One of the greatest advantages of surgery, other than that it can be used to cure some cancers, is that it can make other treatments work better. Indeed, surgery plays an important role in the prevention, diagnosis, definitive treatment, and rehabilitation of the cancer patient.
Reasons for surgery:
1. Diagnosis of Cancer A surgical biopsy is always required to make a definitive diagnosis. A biopsy may be obtained before the tumor is treated, if it might change your willingness to treat or change the way your veterinary health care team will treat the tumor. Surgery is then often employed to remove part or all of the cancer.
2. Curative Surgery for Primary Cancer For the best chance of achieving a surgical cure, complete surgical removal of the tumor should be the first treatment choice. A curative surgery for cancer is the most common use of surgery as a treatment for cancer.
3. Surgery for Tumor Left after a Prior Surgery The best opportunity to cure a pet with a malignant disease is with the first surgery. However, tumors are sometimes incompletely removed with a first surgery requiring subsequent therapy. Surgery to “debulk” a tumor (i.e., surgery to reduce the size of a tumor rather than completely remove it) is rarely an acceptable form of therapy unless it is used simply as a method to improve the effects of chemotherapy, radiation therapy, or improve quality of life.
4. Surgery for Metastatic Disease Surgical removal of metastases (cancer that has spread to other parts of the body) should be considered in select cases. It is to be considered when it is obvious that the original cancer is not progressing rapidly, and that the metastatic disease is restricted to a single site, or a few sites. This is especially true when the surgery for the metastatic disease will improve quality of life or serve as a diagnostic tool for the management of your pet’s disease.
5. To Improve Quality of Life (Palliation) When a tumor, or its metastasis, results in significant discomfort for your pet, surgery can be employed to improve or maintain the best quality of life. It must be remembered, however, that surgery in these patients will not cure the cancer. Surgery will only make the patient more comfortable.
Chemotherapy is a word that creates an instant emotional response in everyone. Chances are that you, or someone you know, have experienced chemotherapy for the treatment of cancer. Visions of debilitating nausea and vomiting, coupled with loss of hair and lack of energy appear at the thought of having to receive chemotherapy. At first, many are opposed to having their pets go through chemotherapy. However, the reality of chemotherapy for animals is much different from that for human cancer patients. For animals receiving chemotherapy, quality-of-life for the patient is the primary concern. Doses of drugs and treatment schedules are calculated to minimize discomfort to the patient, while providing the most effective defense against the disease. As a result, most people are pleasantly surprised at how well their pets feel while undergoing chemotherapy.
Chemotherapy is used to treat cancer at the tumor site, as well as the cancer that may have spread through the body. Using drugs to stop or reverse the growth of malignant cancer began in the late 1940s. Most chemotherapeutic drugs act directly on cancer cells, preventing them from maturing or reproducing. The goal of chemotherapy is to slow the growth of cancer cells, while producing minimal bad effects on normal cells.
Combining different chemotherapeutic drugs is an important,and often effective strategy in chemotherapy. When drugs are used in combination, they may enhance the activities of each other. Drugs are also combined to minimize their dose-related toxicities. Furthermore, combination chemotherapy helps reduce the development of tumor resistance, since cells resistant to one drug in a combination may be sensitive to another drug. The treatment dose and administration schedule during chemotherapy depends on the type of cancer and chemotherapy method. In some cases regularly scheduled chemotherapy administration will be necessary to control cancer for the rest of the pets life. Practically all chemotherapy drugs have side effects. However, their potential effect against the cancer generally outweighs the possible side effects. Although serious adverse effects can occur with any chemotherapy, there is less than a five percent chance that a patient will be hospitalized with side effects. Below are listed some potential side effects of many chemotherapeutic agents.
Hair Loss (Alopecia) Pets rarely lose their hair, but if they do, they are not bothered by it as much as people are. In most pet animals, hair does not grow continually throughout their lives like it does in people. Therefore, hair loss in pets is rare. Exceptions are certain breeds of dogs, such as poodles, Old English Sheepdogs and other breeds whose hair grows continually. In general, if a pet needs to visit a groomer periodically to be clipped, then the pet may experience some degree of hair loss as a result of chemotherapy. Cats may, however, lose all or most of their whiskers. Hair and whiskers grow back after treatment, although they might be a different color or texture of hair.
Reduction in the Number of White Blood Cells There are various types of cells in the blood. The decrease in the number of infection fighting white blood cells is known as neutropenia. Many chemotherapeutic agents impair the bone marrows ability to produce cells. As a result, neutropenia may occur seven to ten days after chemotherapy. Neutropenia, alone, is not a danger to a patient. However, a patients ability to fight off infection is impaired by neutropenia. All patients are given a complete physical, and a blood test called a complete blood count (CBC) is performed prior to all chemotherapy administrations. Should your pet have a significant reduction in the number of white blood cells, the doctor may wish to perform periodic blood tests, delay a proposed therapy, and/or prescribe antibiotics to protect against infection.
Stomach or Intestinal Discomfort Some patients experience a mild form of stomach or intestinal discomfort two to seven days after a chemotherapy treatment. Doctors usually prescribe medication to try to prevent or treat the discomfort.
Finally, being around family members is an important part of a pets life. During a course of chemotherapy, it is important that you realize that your pet is safe to be around all of the family members. Enjoying normal activities together, hugging, and even kissing your pet are all safe activities. Some precautions to consider include carefully storing chemotherapy drugs away from children, wearing gloves when handling these drugs, never breaking a chemotherapy tablet, and avoiding contact with your pets feces and urine for at least 48 hours after receiving chemotherapy. Ask your veterinary team to provide you with easy-to-understand information about how to prevent exposure to chemotherapeutic agents while your pet is undergoing chemotherapy.
Many people have preconceived notions about what radiation therapy does and what its effect is on the pet with cancer. Radiation therapy is often shrouded in negative misconceptions, however, the healing power of therapeutic radiation has been used to help restore the health and well-being of pets with cancer for decades. Whenever radiation therapy is planned for a pet with cancer, quality of life and freedom from any discomfort is a priority. Like surgery, radiation is a regional treatment. It is usually given to the tumor site and two or three inches of 'normal' surrounding tissue. In order to minimize the adverse effects of radiation therapy and to enhance the control of the cancer, small dosages of radiation are administered over several weeks. During each treatment, your pet will be placed under a light level of anesthesia and a machine will be used to precisely direct the radiation therapy beams over several minutes. The radiation therapist will determine the appropriate dosage and number of treatments to ensure the best outcome possible. When radiation is used with the intent of eliminating or controlling the cancer for a long period of time, 9 to 40 treatments are administered over 3 to 6 weeks. Each treatment takes only a few minutes to administer and the actual radiation is not painful.
Radiation therapy must be performed at a veterinary specialty hospital with trained technicians under the direct supervision of a veterinary oncologist (cancer specialist). There are several facilities on Long Island and in the NYC metro area that perform radiation therapy. If your pet requires radiation treatment a referral to a local specialist will be provided.
Good nutritional support has been shown in people and in animals to not only improve quality of life, but also length of life by enhancing the beneficial effects of surgery, chemotherapy and radiation therapy while at the same time reducing the side effects of these therapies. You can play a key roll in enhancing your pet's quality of life by providing good nutritional support.
The first question many people ask is, "What do I feed my pet with cancer?" The answer is quite simple: anything your pet will eat! But if your pet will eat, then you and your veterinarian should develop a dietary plan that will benefit your special pet. While the ideal cancer diet for the pet is not known, there are some simple concepts that can be followed:
Provide a diet with good aroma and taste
Minimize simple carbohydrates (starches and sugars)
Provide a diet that has high quality protein sources (meat, fish)
Whenever possible, consider enhancing the levels of n-3 fatty acids
March 26, 2007 - Merial, the world's leading animal health company, gained conditional approval from the U.S. Department of Agriculture for a breakthrough vaccine to treat canine melanoma, a common yet deadly form of cancer in dogs. This is the first time that the U.S. government has approved a therapeutic vaccine for the treatment of cancer - in either animals or humans.
The vaccine will initially be available for use by specialists practicing veterinary oncology, so pet owners will want to ask their veterinarians about how to access this treatment option.
Despite your best efforts at providing your pet with all of the cancer fighting options available, there may come a time that you need to consider humane euthanasia. There is no time more difficult than the last days of a pet's life. Regardless of how much time you've had to prepare, the decision to euthanize your friend will not be easy. Throughout the life of your pet, you have been concerned about his/her quality of life. But at this moment, quality and dignity of life become immediate. It is important that your concerns are honored at this time and that you are allowed ample information to make all of the decisions that are ahead. Your entire veterinary health care team will assist you during this time by providing information as well as a concerned, understanding ear.
Perhaps the most often asked question is, "How will I know it is time?" Deciding the actual time is very personal. It is important to remember that there is no incorrect decision, there is only a decision that is right for you. There are many issues to take into consideration. They include your pet's quality of life, the cost of continued care, the time you must invest for continued care, and the kind of life you want your pet to live. Quality of life is a subjective assessment, but it can be judged in part by accounting for things such as appetite, activity and energy level, grooming habits, and attention to daily rituals. It may be helpful to keep some sort of written record of your pet's lifestyle. In that record, you may ask yourself questions like: "Do the bad days and times out-number the good?", "Is my pet able to do the things that make him/her happy?", "How does my pet's day differ now, compared to days before s/he was sick?" The truth is that you will know when the time is right to say goodbye to your special friend.
Grief is a normal manifestation of loss regardless if the beloved friend is a person or a pet. There are many ways for you to work through the grief process. You should be aware that the loss of an animal, like the loss of a family member or friend, could cause physical and emotional changes that can last for weeks or months. You may wish to contact a pet loss support group, pet loss hotline, or local specialists who are knowledgeable about loss, and receptive to helping people who have lost a beloved pet.
If you have a dog or cat that is showing signs that could be related to cancer or another serious disease please call the Merrick Veterinary Group at 516-379-6200 to schedule an appointment today. Remember, early detection is critical in the fight against pet cancer!