Microchips and Cancer

By Jean Hofve, DVM

Recently there have been a couple of articles circulating on the Internet about the “dangers” of microchips and the potential for cancer.

There are several things you need to know to assess this information:

1. The strain of mice used in these experiments are bred to be especially susceptible to tumor formation. The fact that these particular mice develop tumors is not necessarily applicable to cats or dogs.

2. Any injection, bruise, or other trauma has the potential to cause cancer (fibrosarcoma) in cats. The “killed” rabies, feline leukemia, and feline AIDS (FIV) vaccines are more commonly implicated, because they are designed to create more inflammation in the area of injection. But even giving fluids has a remote chance of triggering tumor formation. HOWEVER, the risk is very slight.

3. The chances of even a strictly indoor cat getting out or lost are much higher than the chances of a tumor resulting from a microchip. Very few lost cats ever find their way home; but having a microchip (and hopefully additional identification like a collar) makes it much more likely you will be reunited with your cat.

4. Literally millions of dogs, cats and horses have been microchipped in the last decade or so. In the veterinary literature I could find only ONE published report of a chip-associated tumor in a dog. The majority of veterinarians posting to the Veterinary Information Network do not see it as a problem.

5. To ensue the best result with minimal risk, the chip should be placed slightly off the midline (away from all acupuncture meridians), and a dose of homeopathic Ledum 30C given immediately afterward.

6. Even though my (Dr. Jean’s) own cats are indoor-only, over the years, two of them have accidentally gotten outside. Fortunately they were found quickly. But–all my animals are microchipped; it’s cheap “insurance” and I wouldn’t have it any other way!



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2 comments for “Microchips and Cancer

  1. jhofve77
    June 17, 2011 at 8:09 am

    It is certainly up to the guardian to keep their info current in the microchip database! But even though one of my own cats developed a horrible abscess from a chip, I still microchip all my animals. The technology isn’t perfect, but to me it’s added insurance in case my indoor cats get out…in fact just the other day Sundance waltzed right out the back door as I was taking out the trash. Of course collars and tags are needed, but they can come off, and I’ve seen cats get their jaw or a foot stuck in the collar, not to mention collars catching on fences or trees and potentially hanging the cat. Cats should have breakaway collars, but of course those collars are easily lost. Guardians have to balance the handful of documented cases where the chip has initiated cancer against the hundreds of lost pets who have been returned to their homes, thanks to chips. I don’t worry too much about the conspiracy theories about microchipping people, of course I’m probably past the age where that future will get me! But thank you for writing and expressing your concerns–people should understand both risks and benefits before making that decision!

  2. wk
    June 16, 2011 at 10:54 pm

    I have lost 5 pets to cancer in 4 years. All but one was microchipped. I HATE the chips. Working w/rescues many chips were not registered to the correct owner. Many chips migrate. RFID companies are making a fortune pushing chips. Next will be kids and people. Not everything is as great as it appears to be. Get a good collar and tags on your pets. Best thing is not to let them out! www (dot) ChipMeNot (dot) org
    www (dot) ChipMeNot (dot)org (dot)uk



    Just like vets seem to believe CONVENIA (long acting antibiotic) is so great…it almost killed my small dog & $1400 later she made it after week in intensive care. That shot is killing a lot of cats especially.

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