Chemodectomas In Dogs

Dog running happilyChemodectomas are tumors that grow at the base of the heart. Also referred to as heart-base tumors, they are extremely rare, with fewer than 1% of dogs being stricken. Chemodectomas also tend to be slow-growing and often are not discovered until symptoms arise. Dogs that develop chemodectomas typically are 10 or older. Males and females are equally likely to have this type of tumor, but they are more prevalent in brachycephalic (short snout) breeds such as bulldogs, boxers and pugs. Although chemodectomas grow relatively slowly, the cancer eventually can spread to the lungs or the lymph nodes in the dog’s chest. The tumor also may just grow larger within the heart.

Clinical Signs To Look For

Dogs with chemodectomas may present the same symptoms as a dog with heart disease. Your dog might be coughing or displaying an intolerance for exercise. Since chemodectomas are rare, your veterinarian likely would order tests to rule out heart disease before moving forward with any kind of cancer treatment protocol.


If heart disease is suspected, a visit to a veterinary cardiologist might be recommended before a chemodectoma is diagnosed. A veterinarian or cardiologist may order chest X-rays and perhaps an EKG. Then, an echocardiogram would be used to determine if your dog’s heart is functioning well and would show the tumor’s location. Your vet might order a CT scan to better image the mass and further delineate the tumor’s invasiveness.

Bloodwork and a urinalysis are also typical in working up cancer and heart disease.. Another rule out for a different type of cancer is hemangiosarcomas, which are tumors that arise in the cells that line a dog’s blood vessels.

Treatment Options & Prognosis

There are a few options for treating chemodectomas.

Surgery: Surgery to remove chemodectomas in dogs is considered high-risk, so they are rarely performed. One option is to check with a university that has a veterinary program to see if they would perform such a procedure if it’s needed.

Chemotherapy: Oral chemotherapy drugs can help for more than a year. These pills are given at home typically three days per week or, at times, on an every other day basis. There is a chance for GI upset, among other side effects.

Stereotactic Radiation: An innovative treatment, Stereotactic Radiation, can be used to treat chemodectomas in dogs. Typically, a dog will undergo just 1-3 treatments. Another benefit of Stereotactic Radiation is that, compared with chemotherapy, there are fewer side effects. This form of RT is able to target the tumor in a safer way than actual surgery ever could. A dog that undergoes Stereotactic Radiation may do well for more than a year. The team at PetCure Oncology is qualified to perform Stereotactic Radiation treatments. Damaging the tumor without harming surrounding tissues and organs will help your dog, and that’s the goal of this type of radiation.

Due to the slow growth of chemodectomas, it could be months before a tumor impacts your dog’s quality of life. Some dogs also benefit from heart medications, but sadly many dogs with this type of tumor ultimately end up with heart failure.

SEE ALSO: Pet Hero: Spartacus The Happy Staffordshire Bull Terrier

Find A PetCure Oncology Location Near You

At PetCure Oncology, we provide innovative treatment options for dogs with chemodectomas or other types of cancer. We are supportive and professional and passionate about our mission to prolong your pet’s life, and maintain quality of life, for as long as possible.

For more information about PetCure Oncology and our innovative treatment options, find a location near you today.

Types of Cancers in Dogs

If your dog is displaying any symptoms of cancer or has been diagnosed with cancer, sort below by cancer type or tumor location to learn more about the most common types of cancer in dogs and available treatment options. Click on the links for more specific information on treatment and real patient stories.


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