At Pleasant Hill Animal Hospital, we understand that your canine companion is not just a pet, but that he or she is a beloved, cherished family member. The mutual bond of love and loyalty between you can make a diagnosis of any form of dog cancer very difficult to hear. Our veterinarians and support staff are empathetic, compassionate and trained to focus on both the emotional and medical aspects of dog cancer.
We are here to guide you both through the diagnosis and treatment process. This includes choosing the best options for effectively, humanely and successfully dealing with canine cancer.
Common Types Of Cancer In Dogs
Unlike many other species of animals, dogs are susceptible to the same types of cancer as humans. Cancer is caused by the uncontrolled growth of cells in the body. These cells can originate in any of the body's tissues. If not found and arrested in time, cancer can expand and connect with the circulatory or lymph systems, and also can spread and infect other tissues in the body. Canine cancer is the leading cause of death for dogs 10 years of age and older. However, half of all cancer in dogs is treatable if it is arrested in its early stages.
The most common types of cancer in dogs are:
- Hemangiosarcoma: This form of dog cancer is an incurable tumor of blood vessels. It occurs more commonly in middle aged or elderly dogs, although dogs of any age and breed are susceptible to it. Certain breeds have a much higher incidence including Golden Retrievers and German Shepherds. Hemangiosarcoma develops slowly and is essentially painless, so is usually not evident until the advanced stages when the tumors are resistant to most treatments. Less than 50% of treated dogs survive more than six months, and many die from severe internal bleeding before there is an opportunity to institute treatment. It can mimic a benign condition and often is diagnosed only after surgical removal of the tumor.
- Mast Cell Tumors: This is cancer of the immune cells responsible for allergies. Mast cells can be found in all tissues of the body but typically form tumors on the skin. They range from relatively benign to extremely aggressive. They are one of the most easily diagnosed cancers by fine needle aspirate, a quick and non-invasive test, and thus can be treated early. Certain breeds of dog, especially Boxers, are at an increased risk for the development of this tumor.
- Lymphoma: This form of dog cancer can affect any dog of any breed at any age. Most of the time, it 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 affects internal lymph nodes, such as those inside the chest or in the abdomen. This can cause trouble breathing and digestive trouble. Generally this form of dog cancer is considered treatable if arrested in its early stages and can be detected by fine needle aspirates. Standard Poodles, Golden Retrievers and Australian Shepherds are a few of the breeds with higher incidence of lymphoma.
- Osteosarcoma: This form of dog cancer is the most common type of bone cancer in dogs, accounting for up to 85% of tumors that originate in the skeletal system. It mostly affects older large or giant breed dogs, although it can affect dogs of any size or age. Osteosarcoma occurs in many areas, but it most commonly affects the bones bordering the shoulder, wrist and knee. A major symptom is lameness in the affected leg, or a very painful swelling. A biopsy is usually needed for diagnosis.
- Brain Tumors: Epileptic-like seizures or other extreme behavioral changes are usually the only clinical signs. CAT scanning and MRI is used to determine location, size and severity. Many brain tumors can be removed by surgery, although not all. Oral chemotherapy and radiation therapy can control some inoperable tumors.
- Bladder Cancer: Some breeds are more at risk for this form of dog cancer than others. This is a slow developing dog cancer, and symptoms may not show for 3 to 6 months. Urinary obstruction and bleeding are common symptoms. This condition mimics other benign bladder conditions and diagnosis may require repeated testing.
- Mammary Carcinoma: Non-spayed female dogs are at high risk for developing malignant mammary tumors, but all female dogs regardless of reproductive state remain at risk. Approximately 50% of these tumors are malignant, and complete surgical removal is recommended if the cancer has not metastasized.
- Malignant Histiocytosis: This dog cancer affects larger sport breeds most often. It occurs as localized lesions in the spleen, lymph nodes, lung, bone marrow, skin and subcutis, brain, and periarticular tissue of large appendicular (limb) joints. Histiocytic sarcomas can also occur as multiple lesions in single organs (especially spleen), and rapidly disseminate to involve multiple organs. Unfortunately there is no reported effective therapy for this form of dog cancer.
- Squamous Cell Carcinomas: It is most often found in the mouth and the nail beds of the toes. Early detection and complete surgical removal is the most common treatment. Radiation treatment can drastically increase the pet's life span. Fewer than 20% of dogs develop metastatic disease. However, SCC of the tonsil and tongue are quite aggressive and fewer than 10% of dogs survive 1 year or longer despite treatment measures.
- Mouth and Nose Cancer: This is a very common form of dog cancer, more so in the mouth than the nose. Symptoms include a mass on the gums, bleeding, odor, or difficulty eating. About half of mouth tumors are malignant and half are benign. For malignant tumors, early and aggressive treatment is essential. Cancer may also develop inside the nose of dogs. Bleeding from the nose, breathing difficulty, or facial swelling are symptoms that may indicate nose cancer. Special diagnostics such as MRI and endoscopy may be required for diagnosis.
- Melanoma: This form of dog cancer most commonly occurs in canines with dark skin. Melanomas arise from pigment producing cells called melanocytes, which are responsible for coloring the skin. 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. 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 by the time they are first noticed, making complete surgical removal impossible. However, new vaccines are giving veterinarians another tool to fight this cancer and extend patient lives.
- Testicular: This form of dog cancer is common in unneutered dogs with retained testes. This form of dog cancer is largely preventable with neutering, and curable with surgery if arrested early in the disease process.
Symptoms And Signs Of Cancer In Dogs
Some signs of cancer in dogs are easy to spot and others are not. Signs of cancer in dogs may vary greatly depending upon a number of factors. However, the following list identifies some of the most common signs of cancer in dogs:
- Lumps and bumps underneath a dog's skin
- Abnormal odors emanating from the mouth, ears or any other part of the body
- Abnormal discharge from the eyes, mouth, ears or rectum
- Abdominal swelling
- Non-healing wounds or sores
- Sudden and irreversible weight loss
- Change in appetite
- Coughing or difficulty breathing
- Lethargy or depression
- Changes in bathroom habits
- Evidence of pain
Should you witness any signs of cancer in your dog, we strongly recommend making a veterinary appointment immediately.
What You Need To Know About Tumors In Dogs
The term tumor doesn't always equate to cancer. Growths, called tumors, on a dog's body may be malignant, meaning it may:
1) grow and destroy the tissue around it,
2) be prone to spreading to other areas of the body
3) release chemicals that make the dog feel sick in other ways.
The tumors may be benign, meaning they can grow in size, but are not prone to spreading or causing more life altering changes. Some tumors can be easily felt and found by owners at home or veterinarians on physical exams. Others are difficult to detect and are only found when the dog shows other signs of illness. Unfortunately , there is no one blood test for cancer. Early detection and treatment are key to preserving your dog's health and quality of life. Therefore, it is important to periodically inspect your canine companion for any abnormal lumps, pay attention to your dog's appetite, urination and defecation behavior, breathing pattern and energy level and bring your pet in for yearly or twice yearly exams.
Diagnosing Canine Cancer
Only a veterinarian can accurately diagnose canine cancer. This is why it is extremely important to schedule periodic wellness exams for your canine companion. During these preventive exams, your veterinarian can check your dog for signs of canine cancer. If abnormal masses are found or other suspicious symptoms are present, specific tests may be needed to confirm the presence and type of cancer. Based on the intricacy of the test, they may be run at Pleasant Hill Animal Hospital, or recommended through a board certified specialist. Treating canine cancer before it advances is key to successful recovery.
Treatment Options For Dogs With Cancer
Several factors influence cancer treatment decisions for dogs with cancer, including:
- Age of the dog
- General health of the dog
- Tumor type
- Biological behavior of the tumor
- The Stage of the Cancer
The patient's overall health status plays a major role in therapy choices for dogs with cancer. This includes evaluating the patient for his or her ability to tolerate cancer treatment. Life expectancy should be taken into consideration as well; for a slow-growing tumor in an older dog, for example, treatment drawbacks may outweigh potential benefits.
Treatments for dogs with cancer are similar to human therapies, which can include:
- Radiation therapy
- Holistic or herbal therapy
If your dog would benefit from many of these options, our office will refer you to a board certified cancer specialist, an oncologist, to get the most current and effective treatments available. These are important issues to address with the veterinarian at your next appointment.
Make An Appointment Today If You Suspect Dog Cancer
If you suspect dog cancer, whether finding a bump or witnessing behavioral symptoms, please contact us immediately to schedule an appointment. Our veterinarians and support staff will provide you and your canine companion with compassionate, comprehensive dog cancer care and support services. Although dog cancer can be overwhelming, you don't have to go through it alone. We are here to help ease your dog's pain and suffering and eliminate the cancer through the best dog veterinary care available.