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LeonNovember 28, 1995 – March 30, 2006

In April 2004, a French bulldog named Léon developed a high-grade fibrosarcoma (an aggressive form of cancer) at the site of his microchip implant.  In order to determine the best care for Léon, his owner wanted to know why the little bulldog developed cancer.  His owner says:

“I knew that in order to select the best medical treatment for Léon, it was important to determine what caused the cancerous mass.  As the microchip implant was at the site of the growth, I began to research the topic of cancer caused by microchip implants.  I found scientific literature that proves that microchips have caused cancer in animals.  I also found literature that shows there are a wide variety of serious health risks associated with these implantable devices.”

In addition to learning about the health risks associated with microchip implants, Léon’s owner learned how difficult it can be to report an adverse reaction and have it documented in a scientific journal.  Léon’s owner eventually found researchers who not only reviewed Léon’s case but also wrote a scientific paper about it.  Léon’s paper is entitled Fibrosarcoma with Typical Features of Postinjection Sarcoma at Site of Microchip Implant in a Dog: Histologic and Immunohistochemical Study.  It is published in the July 2006 edition of Veterinary Pathology.

Still, many questions remain unanswered:  “Why was it such a challenge to find a laboratory to do additional testing on Léon’s tissue samples?  Why was it such a struggle to report his adverse reaction and have it scientifically documented?  Why aren’t veterinarians required to report adverse reactions to microchip implants?  And, if it was this difficult to document Léon’s case, how many undocumented adverse microchip cases exist?” asks Léon’s owner.

Although deeply saddened by the illness and eventual death of Léon, the unrelenting courage that Léon showed throughout his illness inspired his owner to create a website that examines the dangers associated with microchip implant technology.

To read more about Léon’s story and the lessons to be learned from it, please visit

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