We strongly support the creation of a formal national registry of adverse reactions.
Click below to read recommendations for each of the parties concerned with animal welfare:
* Pet Owners
* Veterinary Oncology Researchers
Recommendations for Pet Owners
There have been no large-scale, statistically valid, clinically controlled, experimental studies involving microchip implants in dogs and cats, so we know very little about their long-term safety. However, the fact that we have not seen an epidemic of cancers in pets would suggest that only a small number will be impacted. As the chip-removal procedure may be both costly and invasive, pet owners may wish to leave the implanted microchips intact within their animals unless a problem surfaces.
Owners of pets that have been implanted should regularly check the area around the chip for any abnormal lumps or swelling. If something unusual is found, it should be immediately reported to a veterinarian, and tests should be done to rule out cancer. The pet owner may be the key to detecting a problem in the early stages and saving the life of a pet. In the two cases where dogs developed tumors around and attached to implants, it was the owners' astute eye and probing fingers that found the cancers, not the veterinarian. The only indication that there was a problem was the lump; all other laboratory tests came back within normal ranges.
If a pet is not currently microchipped, it may be best to keep it that way. It is the opinion of this researcher that all further implantation of pets should be halted until the existing population of chipped dogs is carefully assessed for adverse reactions, including cancer. There are other ways to ensure a pet is returned to its owner in the event it goes missing. A well-made collar and a clear, legible tag with the owner's contact information are effective tools that have worked for generations of pet owners.
Recommendations for Policy-Makers
Given the clear, causal link between microchip implants and malignant tumors in laboratory rodents and dogs, it is strongly recommended that policy makers reverse all policies that mandate the microchipping of animals under their jurisdiction or control. These include ordinances passed by state and local authorities, policies implemented at animal shelters, and formal positions adopted by animal welfare, affinity, and interest groups across the United States and around the globe.
We believe that mandatory microchipping ordinances should be repealed and replaced with a voluntary system of microchipping at the discretion of pet owners. Any pet owner who chooses to have a microchip implanted in his or her animal should be fully informed of the potential risks of the procedure. No one should be forced by law or otherwise coerced into implanting an animal against his or her conscience or medical judgment.
Recommendations for Veterinarians
Veterinary offices are among the most likely places for implant procedures to be performed. Since veterinarians are often the primary point of contact for pet owners on the topic of microchipping, veterinarians should familiarize themselves with the research findings and carefully consider the potential for adverse reactions before recommending implants for their patients.
Pet owners should be clearly advised of the research linking the microchip to cancer in rodents and dogs when seeking advice about the chipping procedure or requesting the procedure for their pets.
In the case of animals that have already been implanted, Vascellari et al. suggest that veterinary surgeons should routinely palpate the tissue surrounding microchip implants as part of routine medical care. Any lumps or inflammation should be investigated for cancerous or pre-cancerous changes. To avoid the complicating risk of injection-related sarcoma, veterinarians should avoid administering vaccines or other injections at or near the site of an implanted microchip.
Finally, veterinarians should advise pet owners to routinely examine the site of the implanted microchip themselves and immediately report any abnormalities.
Recommendations for Veterinary Oncology Researchers
There is fertile ground for additional research in this area, and systematic study would add greatly to our understanding of the process of tumorigenesis as related to microchip implants. Other than preliminary research involving very small number of animals (e.g., Ball et al.; Rao and Edmondson), there have been no studies to date that have systematically examined the development of microchip- induced sarcomas as a research goal in itself. Almost all of the cancers reported herein arose incidentally, in the course of other research.
One important direction for future research would be to explore the role played by electromagnetic energy transmitted by the transponder. This could help determine whether the tumors stem from a foreign-body reaction to the external surface of the microchip alone (i.e. glass capsule and polypropylene sheath) or whether some characteristic of the device in its capacity as a radio- frequency transponder could be responsible for the tumors. A study could be designed to investigate the role of radio-frequency energy by implanting some animals with intact transponder devices and others with empty capsules. In each of these groups, animals could be exposed to different levels of energy from the reader, as well.
Proposal to Create a National Registry
The research community should take advantage of the fact that there are already millions of chipped dogs in the U.S. Rather than conducting further, potentially painful and invasive studies on dogs and other animals, we can study animals that are already chipped to learn more about how living creatures respond to these devices.
Doing so would require the creation of a central registry for reporting adverse reactions to microchips, including cancer. This web site (www.chipmenot.com) is an effort to begin this process, but we encourage the creation of a more formal registry.
Such a registry could be created in one of the following ways:
• Dogs undergoing treatment for cancer could be voluntarily reported to an independent registry set up for this purpose. Because microchip-induced cancer may metastasize and lead to cancer in other parts of the body, it is important to rule out the microchip as the source of cancer in dogs. Veterinarians would report the chip status of all dogs with cancer under their care, and a statistical analysis could be made to determine whether chipped dogs have a higher overall incidence of cancer than their non-chipped counterparts.
• On a voluntary basis, veterinarians could remove the microchip and surrounding tissue from deceased pets and send them to a laboratory for histological analysis.
Done on a large scale, these measures would provide important data that could be used to assess the safety of microchip implants in dogs. Establishing national registries for adverse reactions and evaluating tissue samples would provide a more systematic way of assessing the risk than the current state of relying on case-by-case and anecdotal reports alone.