By Jean Hofve, DVM
I’ve been seeing some articles about the “dangers” of microchips and the potential for cancer.
There are several things you need to know, in order 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 hypersensitive mice develop tumors is not applicable to cats or dogs.
2. Any injection, bruise, or other trauma has the potential to cause cancer (fibrosarcoma) in cats secondary to inflammation. In one notable case, a surgical staple initiated a cancerous growth. 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–a procedure used on thousands of cats every day–has a remote chance of triggering tumor formation. Fortunately, the risk is very slight.
3. The chances of even a strictly indoor cat getting out or lost are much, 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 veterinary literature I could find only ONE published report of a chip-associated tumor in a dog. The renowned pathologist at my alma mater, Colorado State University, said she had seen only one in her entire career.
5. To ensure the best results with minimal risk, I recommend that the chip should be placed slightly off the midline and away from all acupuncture meridians (particularly the bladder meridian, which runs parallel to but a small distance away from the spine), and a dose of homeopathic Ledum 30C given immediately afterward.
6. I advocate microchipping even though one of my own cats produced a spectacular sterile abscess that covered his shoulder and halfway down his leg. So I’ve seen a nearly-worst-case scenario, but I still chip.
7. Even though my (Dr. Jean’s) own cats are indoor-only and not committed door-runners, occasionally one will accidentally get outside. Fortunately I’ve caught or found them quickly with no harm done. But ALL my animals are microchipped; it’s cheap “insurance” and I wouldn’t have it any other way!