January 13, 2021 By Taylor Froiland, PharmD 0

The Most Common Cancers in Dogs

At ExpressVet, we understand that your dog is a part of the family. As a dog owner myself, I can tell you that when my dog or cat is sick or not feeling well, it cuts deep. And the fact that they can’t tell us where it hurts or what is wrong makes the whole situation even worse. The mutual bond of love and loyalty between you and your dog can make a diagnosis of any form of dog cancer very sad to hear and difficult to process.

But it’s important to understand cancer in dogs nonetheless.

Cancer in Dogs

Unlike many other species of animals, dogs are susceptible to many of the same types of cancer as humans are. Just like in humans, dog cancer is caused by the uncontrolled growth of cells in their bodies. These uncontrolled growths are more commonly known as tumors, and they can originate in any of your dog’s body’s tissues.

Cancer is the leading cause of death in dogs over the age of 10. That’s because if it’s not found and treated in time, the cancer can expand and connect with the circulatory or lymph systems, spread throughout the body, and infect other tissues within other organ systems.  However, about half of all dog cancers are treatable if they are caught and arrested in their early stages.

Below are the most common types of cancers in dogs.

·         Mast Cell Tumors - Mast cell tumors are a form of skin cancer.  Mast cells are cells that reside in the connective tissues, especially the vessels and nerves that are close to the external surface of your dog (skin, lungs, nose, and mouth).  Mast cell tumors are graded according to their location in the skin, presence of inflammation and how well they are differentiated.

·         Melanoma - Melanoma is a common type of cancer in dogs and is the most common malignant tumor of a dog’s mouth.   Skin tumors are among the most common tumors found in dogs and many are benign.

·         Lymphoma - Lymphoma is a cancer of a type of blood cell (lymphocytes) and lymphoid tissues.  Lymphoid tissue is normally present in many places in the body, including lymph nodes, spleen, liver, gastrointestinal tract and bone marrow.

·         Bone Cancer (Osteosarcoma) - Osteosarcoma refers to the most common bone tumor found in dogs. Bone cancer can affect any breed of dog, but it is more commonly found in the larger breeds.

·         Hemangiosarcoma - Hemangiosarcoma is a highly malignant cancer that can spread rapidly, causing tumors almost anywhere in the body. It is most often found in the dog’s heart and spleen. Many times it is in the advanced stage before it is diagnosed.

·         Brain Tumors – Brain tumors can cause epileptic-like seizures or other extreme behavioral changes. These are usually the only clinical signs. CAT scanning and MRI is used to determine location, size and severity. Although some oral chemotherapy and radiation therapy can control some inoperable tumors, surgical intervention may be recommended if the tumor is operable.

·         Bladder Cancer - Some breeds are more at risk for this form of dog bladder 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.

·         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.

Signs and Symptoms of Cancer in Dogs

Although they are not always simple to identify, there are signs and symptoms of dog cancer that are easy to spot. Below is a list of common cancer symptoms 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

If your dog has been diagnosed with any type of cancer, the most important thing to do is not to panic. Canine cancer can be very treatable if caught early so it is critical that you discuss treatment options with your vet as soon as possible. 

If you suspect your dog may have cancer before a diagnosis, then bring them in to your vet as quickly as you can so they can examine your pet and determine for sure whether or not cancer is the cause of their symptoms. Then work with them to determine the next steps.