Do Microchips Cause Cancer?

Weighing potential risks and benefits

Scanning a microchip in a dog

Sternrenette (Own work) [ CC BY-SA 3.0]/Wikimedia Commons

The pet microchips and cancer question has surfaced and re-surfaced over the years, causing worry for those who have had their pets microchipped. Is there a risk? Are microchips worth it? Let's look at the pros and cons.

The Pros

  • Millions of dogs, cats, horses, llamas, and other animals have been microchipped without any reported problems. (A few people have been microchipped too.)
  • Thousands of animals have been reunited with their people after becoming lost or stolen. According to one microchip manufacturer, 10,000 pets are reunited with their people each month thanks to their microchips.
  • Microchips work even after collars break or tags fall off.
  • AAHA has created the Universal Pet Microchip Lookup site to assist vets, shelters and pet owners in microchip lookup and reuniting pets and their people.

The Cons

  • Potential for injury or infection with implantation.
  • On rare occasion, microchips have migrated to other areas of the body other than the shoulder area.
  • Some animals have been reported to have tumors at the microchip location. Was the tumor caused by the chip? The exact cause has not been proven at this time.

Do Microchips Cause Cancer?

The main cancer studies cited have involved mice, who don't share the same biological system as dogs and cats. It is unknown if it was the chip material itself or the process of the body dealing with foreign material in the mice studies. But many genetic lines of mice are more susceptible to developing soft tissue cancer after an injection, implant, trauma, or other foreign material is introduced under the skin. As well, the microchip is relatively larger in size for a mouse than for a cat or dog, which may raise the risk.

The good news is that the British Small Animal Veterinary Association has had mandatory reporting of any adverse incidents involving microchips since 1996. In the 13 years up to 2009, 3.7 million pets in the United Kingdom had microchips implanted and there were only two reports of tumors. As a result, the World Small Animal Veterinary Medical Association Microchip Committee concluded that the benefits of microchip implantation far outweighed the potential health risks.

At this time, cases of cancer or other adverse reactions to microchips in the United States are self-reported rather than required.

Are Microchips Worth the Risk?

The American Veterinary Medical Foundation (AVMA) says the risk to pets is very, very low and is far outweighed by the benefit of getting the pet back if lost. They caution against removing the microchip because it requires general anesthesia and surgery.

Other safety devices—seat belts, baby gates, even dog leashes—have had reports of animal injuries or deaths from accidents or improper use. Considering that millions of pets have been microchipped without incident, thousands of lives saved, and the cancer findings (related or not) represent a very small fraction of 1 percent of the total pets microchipped, the benefit outweighs any potential risks.

Keep Your Microchip Information Updated

Microchips must be registered with current information—phone numbers, addresses, and other contact information. It is always sad to find a lost pet with a microchip, but with out-of-date contact information. Contact the organization who microchipped your pet or have your pet rescanned at your veterinarian to ensure that your pet's chip information is up to date. Use August 15m Check the Chip Day, as a reminder to ensure the chip is still working and has updated information.