I began to read everything I could about Vaccine Associated Sarcoma (VAS). I still didn’t know at this point if Chicken’s tumor was vaccine-related because I was waiting for the biopsy results.
What I learned is that these kinds of cancers are under-reported, so the exact incidence is heavily debated. Some say it affects 1 in 1,000 cats, some say 1 in 10,000.
You can learn the basics about VAS here.
I began to research board certified oncologists and radiologists in Cincinnati, just in case. I contacted my vet and got all of Chicken’s vaccination records. She hadn’t been vaccinated since December 29, 2009 so I was hopeful that this tumor would turn out to be just a fatty mass. Vaccine associated sarcomas can show up anywhere from a month after vaccination to 10 years post-vaccination. I found out that on 12-29-09 Chicken was given both Leukocell 2 (FeLV) and Defensor 3 (rabies) adjuvanted vaccines. I also learned that all animals should be vaccinated as low on the legs as possible so that if VAS develops, the leg can be immediately amputated to increase the pet’s survival chances. The AVMA has been recommending this to vets for the past ten years. I guess my vet didn’t get that memo.
VAFSTF Vaccine Site Recommendations
I also found out that many animals are over-vaccinated.
AVMA Vaccination Brochure