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No clear link between microchip implants and tumors in animals, says WSAVA
Salina Christmas, Web Editor
19 November 2007
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| It is dangerous to transpose results from experiments in one species, such as GM mice bred for cancer research, to companion animals, says WSAVA |
The statement was made on the WSAVA website recently in mid-October in response to reports of concerns about a possible link between the implantation of RFID transponders and the formation of tumors in animals. The reports were brought to the attention of the WSAVA Microchip Committee.
In September 2007, Associated Press highlighted the link between RFID transponders and tumors in laboratory mice in its news report on microchip implants in human beings. The report questioned the US Food and Drug Administration’s endorsement of such move.
Associated Press reported that a few studies published in veterinary and toxicology journals between 1996 and 2007 found that subcutaneous sarcomas sometimes developed around the microchip implants injected into laboratory mice and rats.
A French study in 2006 spoke of tumors associated with microchips collected from three mice studies (Experimental and Toxicologic Pathology; Issue 57 No 4, March 2006).
In 1999, another study mentioned the sarcoma that developed within the tissue capsule which surrounded the transponder in 18 of the 177 laboratory mice under observation (Toxicologic Pathology; Issue 27 No 5; Sept-October 1999).
The WSAVA Microchip Committee at its meeting in October, stated that it has reviewed the available evidence and come to the conclusion that from the tiny number of such cases reported compared to the huge numbers of animals that have been implanted, the effect is extremely small.
 The WSAVA Microchip CommitteeThe Microchip Committee was established within WSAVA about 10 to 12 years ago. There are seven people in the Committee. The Committee's objective is to promote the WSAVA's interest and views in relation to RFID › Visit the website |
“The Committee is aware of more recent scientific papers which have reported tumor formation at the site of implanted transponders in mice. The mice involved in these studies were either inbred strains or strains that have been genetically modified to predispose individual animals to cancer formation.
“Many studies show that it is dangerous to transpose results from experiments in one species to other species, for example from genetically modified mice to normal pet dogs and cats.
“Transponder safety has been reviewed by many national regulatory authorities responsible for the approval of implantable medical devices. These authorities have approved transponders as safe and effective ways of permanently identifying animals. Such approval would not have been granted if there had been significant evidence that implanting transponders could induce tumor formation in the domestic animals concerned.”
The Committee was backed by Dr Linda Lord, an RFID researcher at Ohio State University, who said: “There is no evidence to suggest that companion animals implanted with a microchip are at a higher risk for developing a tumor. The mice used in the studies where an association between a microchip and development of a tumor occurred were genetically predisposed to cancer and do not represent the genetic diversity we see in our dogs and cats.
| Related Studies |
| Experimental and Toxicologic Pathology; March 2006 Subcutaneous microchip-associated tumours in B6C3F1 mice: a retrospective study to attempt to determine their histogenesis Le Calvez S, Perron-Lepage MF, Burnett R Experimental and Toxicologic Pathology; 1997 Subcutaneous soft tissue tumours at the site of implanted microchips in mice Tillmann T, Kamino K, Dasenbrock C, Ernst H, Kohler M, Morawietz G, Campo E, Cardesa A, Tomatis L, Mohr U Toxicologic Pathology; 1990 Tissue reaction to an implantable identification device in mice Rao GN, Edmondson J Comments? Email us |
Dr Lord said she is more concerned about her pets getting lost and finding them.
“When you weigh this extremely rare event against the thousands of pets that are reunited with their owners worldwide each year through using a microchip, it seems obvious that the benefits from microchipping far outweigh any small risk from a tumor,” she said. “All of my pets are microchipped and all my future pets will be as well.”
In the Associated Press report, a veterinarian oncologist at Ohio State University, Dr Cheryl London, was quoted as saying: “It's much easier to cause cancer in mice than it is in people. So it may be that what you're seeing in mice represents an exaggerated phenomenon of what may occur in people."
The WSAVA Microchip Committee said: “While it is not possible to claim that the reaction to an implanted transponder in a companion animal will never induce tumour formation, the Committee is unanimously of the opinion that the benefits available to implanted animals far outweigh any possible risk to the health of the animal concerned.
“Millions of animals have carried their transponders for most of a natural life time without any adverse effects,” it emphasized. “Conversely many thousands of implanted animals have been reunited with their owners after going missing by tracing the owner through a reliable database.”
NOTE: In order to monitor the situation, the WSAVA Microchip Committee would be interested to receive details of any cases where tumours have developed in companion animals at the site of transponder implantation, and where there is suspicion of an association. In the first instance, details should be sent to the WSAVA secretariat at fasanne@fasanne.dk
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