October 2023

In this VETgirl sponsored online veterinary continuing education blog, guest blogger Christopher Lee, DVM, MPH, DACVPM discusses Feline Injection Site Sarcoma (FISS) in cats, and understanding it from a different perspective. Read on to find out how veterinarians have to balance all therapies and prophylactics with judicious use to protect our feline patients!

Feline Injection Site Sarcoma (FISS) from a Different Perspective

By Christopher Lee, DVM, MPH, DACVPM

Imagine a new human pandemic consistently infecting two to three percent of the population. Within the US, this percentage equates to six to ten million infected people. Since the virus is excreted in saliva, nasal secretions, urine, and feces, close contact, shared use of bathrooms, and eating together readily transmits the infection.

Once infected, your median survival time would be two and a half years – within 30 months, you will likely be dead. The road to death will not be pleasant and will be filled with fever, loss of appetite, lymphadenopathy, pain, diarrhea, weight loss, and various neurologic disorders. Persistent viral infections cause cancer in thirty percent of victims.

cat looking outside

Image by Dee from Pixabay

Tragically, the most susceptible population is children. Despite this, adults remain susceptible, and no cure exists. Once exposure is high enough, anyone can be infected.

Yet, a vaccine exists. Some companies boast a 100% preventable fraction at one year, and one is licensed for protection for two years. Still, some doctors are reluctant to vaccinate you over concerns about a severe negative reaction.

However, this same reaction has been identified with other vaccines and injectable medications (antibiotics, steroids, fluids) that the same doctors readily administer and have even been associated with localized tissue trauma. When looking at the data, the national medical association cites that the rate of severe negative reaction is well below one per ten thousand injections. Even at one per ten thousand, this would equate to thirty-three thousand deaths versus six to ten million deaths.

Vaccination remains a numbers game. This explains why the CDC recommends “annual influenza (flu) vaccination for everyone 6 months and older in the United States” but does not recommend anthrax, yellow fever, rabies, typhoid fever, or Haemophilus influenzae type B for civilians. In fact, only at-risk military personnel regularly receive these additional vaccines.

Why? The risk outweighs the reward.

Doctors provide vaccines to healthy individuals within at-risk populations. This, in turn, protects those individuals, and by extension, commonly known as herd health, to others.

Here lies the dire situation for cats with their pandemic, technically a panzootic, known as the feline leukemia virus (FeLV). Should we worry about feline injection site sarcoma (FISS)? Yes, as with every injection we provide to a feline patient.

The balance of risk and reward is a dangerous task. What do the experts say? The American Animal Hospital Association (AAHA) recommends the FeLV vaccine as core for all kittens. Young felines should be boostered at one year and, thereafter, vaccination is based on lifestyle. Any cat who may encounter other cats of unknown FeLV status should be annually vaccinated… Translation: Cats who go outdoors or mingle with cats who go outside remain at risk for FeLV, regardless of age.

vaccine syringe

Image by Arek Socha from Pixabay

The FISS rates mentioned above arise from a 2018 American Veterinary Medical Association (AVMA) publication. Since the inception of medicine, doctors have had to balance all therapies and prophylactics with judicious use. Overuse of any aspect of medicine jeopardizes the lives we seek to protect. Similarly, underuse of them does the same.

As veterinarians, we face difficult choices and balance risk daily. We make our best decisions in an imperfect world. Tomorrow, everything may change, but today, we must stay strong and make the best choice with what we know and have.

References:
1. Bureau, U. C. (2023, August 7). Census.gov. https://www.census.gov/Population Clock (census.gov)
2. Burns, K. (2018, November 14). The continuing conundrum of feline injection-site sarcomas. American Veterinary Medical Association. https://www.avma.org/javma-news/2018-12-01/continuing-conundrum-feline-injection-site-sarcomas
3. CDC. (2022a, January 24). Recommended vaccines by disease. Centers for Disease Control and Prevention. https://www.cdc.gov/vaccines/vpd/vaccines-diseases.html#travel
4. CDC. (2022, August 25). Seasonal flu vaccines. Centers for Disease Control and Prevention. https://www.cdc.gov/flu/prevent/flushot.htm
5. Cornell Feline Health Center. (2016, May). Feline leukemia virus. Cornell University College of Veterinary Medicine. https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/feline-leukemia-virus

Nobivac logo

This VETgirl online veterinary continuing education blog is sponsored by Merck Animal Health. Please note the opinions in this blog are the expressed opinion of the author(s), and not directly endorsed by VETgirl.

Only VETgirl members can leave comments. Sign In or Join VETgirl now!