Aortic Body Tumors in Cats and Dogs
What are aortic body tumors?
Aortic body tumors (also referred to as chemodectomas) are abnormal growths of the chemoreceptor organs. These
chemoreceptor organs play a variety of roles and influence changes in respiratory and cardiac function. There are several
chemoreceptor organs throughout the body, but among these, the aortic body is one of the most common sites where
abnormal growth occurs. The average age of dogs and cats at the time of diagnosis of aortic body tumors is 10 years.
Approximately 52% of animals with an aortic body tumor will also show abnormal growth in another organ, most commonly
interstitial cell tumors and thyroid carcinomas.

How common are aortic body tumors in cats and dogs?
Aortic body tumors are infrequent in dogs and very rare in cats (only 6 cases reported in the literature). They can be either
benign or malignant, and malignant tumors have been reported to spread to the lungs, lymph nodes, liver, bone, and other
organs. In one study of 357 cases of chemoreceptor tumors in dogs, only 12% of aortic body tumors had distant
metastases, most frequently to the liver and lungs. In cats, metastatic disease was seen in 3 of 6 cases. Certain breeds
appear to be at higher risk for aortic body tumors, namely boxers, Boston terriers, English bulldogs, and German
shepherds.

What are the symptoms of aortic body tumors in cats and dogs?        
Heart tumors in general can cause varied clinical symptoms depending on their size, location and whether they ruptured
and caused internal bleeding. The observed clinical symptoms are typically seen due to the obstruction of blood flow into
or out of the heart, interference with effective pumping of the blood and/or disruption of normal heart beat. The heart is
enclosed in a sac called the pericardium and aortic body tumors have been shown to cause bleeding into the sac (referred
to as pericardial effusion), and when the blood overfills the sac (referred to as cardiac tamponade), the heart's function
may be compromised. The most common signs in animals with heart tumors include fainting, shortness of breath, lack of
appetite, weight loss and general weakness, which can range from subtle to severe.

How is the diagnosis made?
Diagnosis of an aortic body tumor typically involves evaluating the pet's history, clinical signs, physical examination, and
several other tests such as complete blood cell count, biochemical profile, urinalysis, electrocardiogram, chest and
abdominal X-rays, and chest and abdominal ultrasound examination. The blood and urine tests are done to evaluate if the
pet has any concurrent medical condition, but will not specifically detect the presence of an aortic body tumor.
Electrocardiogram analysis (an instrument that records the electrical activity of the heart over time; commonly known as
EKG or ECG) evaluates the heart's function and may detect some abnormalities. The chest and abdominal X-
rays/ultrasound will help to evaluate the extent of the disease as well as whether the tumor has spread to other organs.  
Recently, more advanced imaging techniques such as CT scans are being used in evaluating the pet's condition,
especially when determining if the tumor can be surgically removed.

What are the treatment options for aortic body tumors in cats and dogs?
Surgical removal of the aortic body tumors is the treatment of choice, but the location and characteristics of these tumors
make surgery difficult. Radiation therapy has been used in a limited number of cases, but its benefit in terms of overall
survival is not yet known. There is some evidence that surgical removal of the pericardium (the sac that contains the heart)
at the time of biopsy can greatly improve the quality of life and life expectancy. In one study of 24 dogs, the median survival
time following the pericardium removal surgery was 730 days, whereas the median survival time for dogs who did not
undergo the treatment was 42 days. Another study with 25 dogs showed similar survival benefit associated with the
pericardium surgery.

What is the prognosis for cats and dogs with aortic body tumors?
The prognosis for pets with aortic body tumors is guarded to fair.  Average survival time in dogs treated medically is 4
months but the average survival time for dogs that undergo surgical removal of pericardium is 22 months. In cats, the
length of survival ranges from 0 to 19 months, depending on the type of treatment they received.

Are there any clinical trials?
There are no clinical trials specifically designed to treat aortic body cancer in pets but there are several clinical trials
available for cats and dogs with any tumor type for which your pet may qualify. To learn more these trials (which are
partially or fully funded by the institutions), please visit the
Dog Clinical Trials (any tumor type) or Cat Clinical Trials (any
tumor type
) section.  

To learn more about veterinary clinical trials in general, please visit the
Pet Clinical Trials section.

Additional sources

Sources:
  • www.vet.uga.edu/vpp/clerk/bement/index.php
  • Withrow Stephen J, and David M. Vail. Small Animal Clinical Oncology. St Louis: Saunders Elsevier, 2007.
  • Morrison Wallace B. Cancer in Dogs and Cats: Medical and Surgical Management. Baltimore: Williams&Wilkins, 1998.
PET CANCER CENTER
Comprehensive guide to cancer diagnosis and treatment in cats and dogs
© 2007 Pet Cancer Center. ALL RIGHTS RESERVED.
Last updated 4/10/13
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