Vaccine Associated Sarcoma

Posted on June 12, 2015

Vaccinating your cat is an important and critical component in ensuring a long and healthy life for the feline.  Unfortunately in rare cases, vaccination can lead to the formation of a soft tissue growth, referred to as Vaccine Associated Sarcoma.  While the appearance of such tumors remains relatively uncommon, certain vaccines such as the rabies vaccine and FeLV vaccine tend to increase the frequency of such occurrences.  Appropriate and timely vaccination along with proper maintenance and care of the vaccination site are key elements in minimizing the chances of tumor development and growth.

Vaccine associated sarcomas are easily recognizable by the untrained eye as they tend to appear superficially underneath the skin and can be felt as soft and tender lumps.  Such tumors tend to cause very little or no pain and discomfort, but their characteristic finger like projections can be fatal as they allow the tumor to spread to surrounding tissues and limbs.  If left untreated, these tumors can eventually metastasize in distant organs and eventually prove to be life threatening.

As with any other tumor, biopsy is the veterinarian’s most effective tool in assessing and diagnosing your cat.  Further evaluation of the sarcoma can include a comprehensive blood work, CT and MRI exam and even chest X-ray to clinically evaluate any advancement of the growth into the lungs.

Upon recognition and diagnosis, surgery is usually elected as the first mode of treatment in removing the tumors.  Early recognition of the sarcoma is a critical factor in limiting the aggressive nature of the surgery, as advancement of the tumor into limbs can result in amputation in extreme cases.  Thorough and complete removal of the tumor is essential in eradication of the sarcoma and exponentially reduces the chances of regrowth.

In more advanced cases of vaccine associated sarcoma, injection radiation and chemotherapy may be used as tools to complement the surgery and reduce the chances of any reoccurrence.  The unilateral cooperation of the surgical team and the oncologists is essential in making sure that sarcoma cells are removed properly and completely, thus eliminating future complications and ensuing a long and healthy life for your cat.