JAVMA Study Reveals Many Vets Aren’t Following Feline Vaccination Guidelines
In 1991 veterinary medicine suffered a disturbing revelation. Two commonly used feline vaccines were linked to the development of malignant tumors at the site of vaccination. The tumors, called fibrosarcomas, are associated with the vaccines for rabies (in cats only) and feline leukemia. They are aggressive and difficult to remove. They occur in approximately one out of every 3000 – 10,000 cats who receives a rabies or leukemia vaccine.
The discovery of these so-called vaccine associated fibrosarcomas lead to the creation of a special task force (called, unsurprisingly, the Vaccine Associated Fibrosarcoma Task Force). The recommendations of the task force were supposed to cause a dramatic shift in the way cats are vaccinated.
Prior to the discovery of the fibrosarcomas and the formation of the task force, most cats were vaccinated against rabies and leukemia every year. The vaccines were administered between the shoulder blades because that is the easiest place to give injections to cats.
The task force recommended that the leukemia vaccine should be administered only to cats who spend time outdoors. The rabies vaccine should be administered as required by law. If possible, both vaccines should be administered no more frequently than once every three years.
Finally, the task force advised veterinarians to change injection sites. Fibrosarcomas between the shoulders are virtually impossible to remove. Therefore, the leukemia vaccine should be administered in the left rear leg, near the ankle. The rabies vaccine should be administered similarly in the right rear leg. If a fibrosarcoma develops in either of these locations, the cat’s life can be saved by amputating the leg–a less than perfect solution to the problem, but better than the alternative.
Vaccine associated fibrosarcomas are a source of angst for me. I have worked during my career to minimize the number of rabies and leukemia vaccines I give to cats. And I always give the vaccines in the rear legs.
However, a very disturbing paper published in the February 1, 2009 Journal of the American Veterinary Medical Association (JAVMA) indicates that many veterinarians are ignoring the recommendations of the task force and needlessly endangering the lives of their feline patients. According to the paper, significant numbers of cats are developing vaccine associated fibrosarcomas between their shoulder blades. This means that significant numbers of veterinarians are still giving rabies and leukemia vaccines in that spot.
Here are the conclusions of the paper.
Conclusions and Clinical Relevance–Despite publication of the vaccination recommendations, a high proportion of tumors still developed in the [region between the shoulder blades] . . . [v]eterinarians are complying with vaccination recommendations to some extent, but need to focus on administering vaccines as [far down] as possible on a limb to allow for compete surgical margins if amputation of a limb is required. (J Am Vet Med Assoc 2009;234:376-380)
What can you do to ensure that your vet is following the task force’s recommendations? Talk to him or her. Ask whether vaccination for leukemia and rabies is appropriate for your cat. If the vaccines are appropriate, ask where they will be administered. Never accept a one-size-fits-all approach to vaccination.
Photo: A vaccine associated fibrosarcoma between the shoulder blades of a cat, courtesy of Texas A&M’s School of Veterinary Medicine.
You have questions. 
Wow! I knew that over time, most the vets I have seen said every 3 years fur Rabies and DIstemper, but I did not know why. Now, I do. And I know to ask my Dr where they plan on sticking me furst!
Maybe if more patients asked about this, more Drs would follow the practice.
I’m speechless – so glad you have your blog so we can be informed! Thank you for this info!
I’m due for my rabies shot; soooooo glad I have this information!
I recently had a scare when the vet found a lump on my neck/back by my shoulder blades. At my current vets they always do shots in our legs but mum got me as a stray so she didn’t know what my vaccine history before that. Luckily the vet took a small sample and got it tested and its just a lipoma (benign fatty lump) so I’m going to be OK!
Our vet used to give the 3-year shot but now does the yearly one. When Momma asked him about it, he said the yearly one was safer — something about the way the shot was formulated and live virus versus dead virus or something.
The one question that wasn’t addressed here was : What is the time frame from injection to sarcoma? Perhaps the continued development of sarcoma reflects practices from years back? Could a 16 or 17 year old cat develop the sarcoma from shots it got as a kitten? Or have they established that the time frame is quite short? Mom says if I don’t travel anymore, I’m not getting any more shots. (You HAVE to get shots to go on an airplane!)
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Just last week my Vet told us this, saying there is just 1 rabies vaccination that has not shown tumors yet. Its a 1 yr rabies for we felines. Being an Animal Assisted Therapy cat but residing in doors, I still have to have rabies. Oddly, another vet wanted to give me the 3 yr shot – so meowsters check out your vets and question them If they want to give you a 3 yr rabies, find a new vet as the outcome can be very CATastrophic.
Arnold, the JAVMA article stated that the timeframe for tumor development is one to 10 years. It is unlikely that a kitten vaccine would lead to a tumor in a 17-year-old cat.
Regarding the one-year versus three-year vaccines: I have not yet seen conclusive evidence that the one-year vaccine is three times less likely to cause a tumor.
A few years ago I attended a lecture given by a representative of the one-year vaccine’s manufacturer. She claimed that the lack of a vaccine component called adjuvant in the one-year vaccine made it safer. That argument is not universally accepted by experts.
After the lecture I cornered her and asked her point blank whether she had quantitative evidence that giving three of the one-year vaccines was safer than giving one of the three-year vaccines. Her answer was no.
I got this cancer… and I wasn’t able to fight it~ I was eleven when my mommy walked me to the bridge…
Mommy just begs everyone to talk to their vets about shots… and to watch their kitties… my tumors grew QUICKLY both times ( I had MAJOR surgery to remove them once– but they grew back and I didnt have the strength to fight anymore…)
PLEASE let your mommy’s and daddy’s love on you so they know what your supposed to feel like… and they can get you to the doctor early if you do gets a tumor…
Why can’t vets do a rabies titer to see if the vaccine is still active? If it is, then why are we vaccinating our pets, especially cats? I would rather pay for the test first to see if my cat needs it. They insist on giving the vaccine every 3 years. I’m worried….
My sympathies to Chrissy Angel kitty…
I actually had quite the argument with my vet about this right in front of about 3-4 other pet owners.
One he insisted he knew of no vaccines that were only every three years, insisted I come in every year for all my vaccines.
Two I brought up the subject of these tumors and he told me it was very rare, too rare to worry about it. He still does the in between the shoulders vaccination for both of these. If he wouldn’t vaccinate in the legs, I would go elsewhere if my cats were deemed in need of these two vaccines, my cats are strictly indoors so it’s not as much of a risk.
There’s also vaccines without the ‘adjuvants’ common leukemia and rabies vaccines have (which are thought to cause these tumors) from purevax (sp?). I’ve been told Adjuvants are added to make the vaccine last longer. But that was over 6 years ago and it was still new, I have no idea how that went since. Or if it was actually proved to be safer.
My cat, Smokey, has developed this tumor between her shoulders. She will be 17 in April.
For the last 5 years she has been seeing a vet that only gives vacines in the leg. I know of at least one occasion when her previous vet gave her injections in the scruff near her shoulders.
It has been about 8 months since I first noticed it (then about grape sized), the tumor is now about the size of the one shown in the picture at the top of the page. Due to her age, tumor location, and my finances I was unable to have the tumor removed when it was first noticed. At this point she is not in any noticable pain.
Does anyone know how long a cat can live with these tumors untreated? I know my Smokey has many other health issues and it just seemed cruel to subject her to surgery.
I can’t even type this without crying. My 15 y/o tabby Miaka lies next to me on the bed. Last May we took her to a vet school and had a tumor between her shoulder blades biopsied. It was the size of a half of a ping pong ball. Now, 7 months later, it is MASSIVE. It has completely taken over her shoulders, right front leg and has wrapped around her leg to begin encircling her chest. She can no longer walk normally because the mass gets in the way. She so thin, just bones. I think the tumor’s metabolism must be very high and robs her of the calories she eats. She does not seem to be in a lot of pain. I am watching her closely. I know that any day I may see the signs that tell me it’s time to put her down. My vet NEVER mentioned the chance of VAS to me. Now I tell everyone I can. My heart goes out to all who have experienced this.