Implanted Microchips...

[marion]

I have read several times recently that implanted microchips caused tumors in mice and some dogs developped

cancer...could somebody post some info?

 

 

[turbotaina]

I've heard that if a dog is vaccinated in the area of a microchip, fibrosarcomas can form. Someone raised this question a few months ago...See if you can do a search of this forum - I think someone posted some research. And here's an article: VetPathology

 

 

[marion]

Thanks for the info! But it seems that there are also adverse reactions not only in case of implantation on a vaccine area...like it says in the article:

 

[url="However, despite clear advantages over other identification techniques, some adverse reactions to microchips have been recorded.16,17 Some cases of soft-tissue tumors surrounding a microchip have been described in laboratory mice and rats.2,7,19 All the tumors described in these papers were mesenchymal in origin and contained embedded microchips. The mechanism of carcinogenicity was ascribed to a foreign-body–induced tumorigenesis.7 Recently, a case of liposarcoma embedding the microchip (Indexel, Merial) was described in a dog.22 In the present case, the microchip was not embedded within the tumor but was found intimately adjacent to it.

 

[marion]

Here's another article:

 

http://www.thedogplace.com/Articles/DogCar...ochip.RDOWS.htm

 

 

[Guest SoulsMom]

I just posted the full article

[Guest Tigonie]

Microchips have been in widespread use for many years. So have vaccines. The Vet Pathology article primarily refers to a study done on one dog, investigating a tumor next to the microchip near the site of vaccination. Their conclusion is certainly not that microchips cause cancer or tumors, though they think there could be a link with a microchip/vaccine combo and cancer. They basically say they think that more study is necessary:

 

In this case, it is difficult to establish which was the primary cause of the neoplastic growth, because the dog had received several rabies vaccines and the microchip was detected close to but not included in the mass. A concause [a joint cause] could then be hypothesized. Notwithstanding, reports on adverse reactions to vaccination and microchips are strongly encouraged to deepen the current knowledge on their possible role in tumorigenesis. In fact, the cause-and-effect relation between exposure (injection) and the outcome (sarcoma) is still to be defined and is a matter of discussion for experts.

It seems to me personally that without a study of 1000+ microchipped dogs over a long period of time, there is no way to statistically conclude anything about the potential risk. What if the microchip were implanted well away from areas where they usually give vaccinations? Are microchips safe for dogs that don't get vaccines? Is the vaccination causing the cancer and not the microchip? Are non-microchipped dogs getting cancer in the same areas of their bodies at a similar rate? Is the cancer related to something other than the microchip/vaccine combo (e.g., heredity or environment)?

 

Besides, many adoptions now don't give the owner a choice whether or not to microchip--quite a few adoption groups and shelters automatically put a chip in for all animals they adopt out.

 

Here are links to a couple of recent newspaper articles on the topic: a blurb in the Chicago Tribune and a better article with references in the Washington Post. A lot of the debate is about the FDA's approval of putting the chips in humans, since there have been some studies which include animals that had cancer at the site of their microchip. (I know the human microchip debate is off topic for this forum, but even without the thought of cancer, to me that's just creepy!)

Edited September 10, 2007 by Tigonie