Vascellari, Melchiotti, & Mutinelli, 2006: "Fibrosarcoma with typical features of postinjection sarcoma at site of microchip implant in a dog: Histologic and immunohistochemical study." Veterinary Pathology. 2006;43:545—548.

Summary: A 9-year-old bulldog developed a cancerous tumor (fibrosarcoma) adjacent to a microchip implant approximately seven months after being implanted with the device. Researchers attributed the tumor to either the microchip or to vaccinations at the site, and called for better reporting of adverse reactions to microchip implants and vaccinations.