Despite their relatively short life spans, the incidence of cancers and tumors in dogs is rapidly rising. There are many different types of cancer that can occur in dogs, and effectively treating dog cancer depends on the type of cancer the dog has and how quickly it is identified.
Skin tumors are one of the most common types of cancer in dogs. As they age, dogs frequently develop lipomas, which are tumors beneath the skin made up of fat deposits. Many dogs will develop multiple lipomas as they get older, but these fatty deposits cannot be identified as benign (non-cancerous) lipomas by appearance or feel alone. Any mass that develops on your dog should be tested for cancer via a “needle aspirate” or “biopsy.” This procedure involves taking a sample of the cells within the mass, followed by a microscopic evaluation to diagnose the type of mass. If the result is benign, removal is often not necessary, as long as the mass isn’t causing pain or discomfort due to its size or location.
Common Types of Skin Tumors in Dogs
Aside from lipomas, another common type of skin tumor in dogs is the Mast Cell Tumor (MCT). Mast Cell Tumors can be difficult to distinguish from other benign growths or warts that develop on the skin as dogs age, as they can resemble many other types of skin lesions. These tumors are frequently seen on the head and neck but can also appear on the body, legs, and even in the mouth.
Because it’s impossible to visually distinguish mast cell tumors from other benign skin growths, any new or suspicious growth on your dog should be biopsied. If the tumor is diagnosed as a mast cell tumor, surgical excision is the treatment of choice. Tumors can be much larger under the skin than they appear, so your veterinarian will surgically remove a wide area around the tumor to ensure its complete removal. Depending on your dog’s age and medical history, your veterinarian may recommend X-rays to check for other signs of cancer, blood work to assess your dog’s overall health, and potentially a consultation with a veterinary oncologist to determine if radiation or chemotherapy is needed to help control the cancerous cells and prevent the tumor from recurring or spreading.
Spaying or neutering your dog not only helps prevent pet overpopulation and unwanted litters, but it is also one of the most effective ways to prevent dog cancer entirely.
Mammary tumors, like breast cancer in humans, are cancerous growths that occur in the breast tissue. Mammary tumors are among the most common cancers in female dogs and are often fatal. Fortunately, spaying your dog before her first heat cycle reduces her risk of developing mammary tumors to less than 1%, with the risk rising exponentially as she gets older without being spayed.
Mammary tumors occur within the mammary glands and may feel either soft or hard under the skin. Some cause bruising around the mammary gland, while more advanced tumors may lead to open wounds or even bleeding. While about half of mammary tumors that are tested are found to be benign, malignant tumors are very aggressive and can quickly spread throughout the body, becoming fatal.
If your dog develops a suspicious swelling or mass in the mammary area, prompt medical treatment is crucial. Your veterinarian may perform a fine-needle aspiration of the tumor, which will be examined to determine its type and severity. Blood work will also be performed to assess your dog’s general health, as well as chest X-rays to check for any spread of the disease to the lungs.
Surgical treatment is generally a mastectomy, which involves removing the mass along with the associated mammary gland, or sometimes several of them. The surrounding lymph nodes may also be removed if they are involved. Spaying your dog at this time may also be recommended to help reduce the hormones that cause the tumors to form. A consultation with a veterinary oncologist is often suggested, as chemotherapy or radiation therapy may be recommended, especially if the cancer has spread beyond the mammary gland.
Like intact female dogs, male dogs that are not neutered are at a significantly increased risk of developing prostate and testicular cancers as they age. Prostate cancer is almost exclusively found in unneutered male dogs over 10 years old. Due to the location of the gland and its proximity to many important structures and nerves, prostate cancer is usually inoperable. It is typically not detected until late in the course of the disease, and by the time it’s discovered, chemotherapy and radiation are generally the only available treatments, though neither has shown to greatly increase long-term survival for dogs with prostate cancer.
Testicular cancer only occurs in dogs with testicles, so neutered dogs have a 0% chance of developing this disease. Neutering (removing the testicles) is the first step in treating this cancer. After the surgery, further tests and potentially radiation or chemotherapy may or may not be recommended.
There are many types of cancer that can be diagnosed in dogs, and unfortunately, many of them do not manifest until they have spread or the tumors have grown enough to cause other significant health problems. As a result, the best way to treat dog cancer is to maintain a good relationship with your veterinarian and have a strong preventative program in place. While many cancers cannot be prevented, routine physical exams, screening bloodwork, and careful attention at home can help ensure that if your dog does develop cancer, it can be detected and treated early, increasing the chance of survival and potential cure.
