Do Microchips Cause Cancer in Pets?

Weighing the Risks and Benefits

Microchip Pet Scan

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Each year, pets all over the world are microchipped, and with owners becoming more educated about this option, the numbers continue to grow. Unfortunately, questions still come up about whether microchips can potentially cause cancer. We will discuss what a microchip is, what the studies show, if microchipping your pet is a safe method of identification, and whether the benefits outweigh the risks.

What Is a Microchip?

A microchip is a small (about the size of a grain of rice) electronic chip, enclosed in a glass case, that is implanted in your pet by your veterinarian. This chip also referred to as a transponder, is activated when a scanner is passed over the area. Radio waves put out by the scanner actually activate the chip. The chip transmits a unique identification number to the scanner, which is then displayed on the scanner's screen. If your pet is ever lost and brought to a shelter or a veterinary office, the pet is automatically scanned for a microchip, and as long as your information is accurate, you can be reunited with them.

How Is a Microchip Placed?

Because a microchip is so small, it can be implanted in pretty much any type of animal at any age. The small chip is injected under the skin with a large hypodermic needle. Some owners opt to wait until their pet is coming in for their spay or neuter procedure because they feel the large needle will hurt their pet. But it happens so quickly, once they realize they have been poked, it's all over. Once it is placed, make sure to have it registered with information like your name, phone number, and address. Displaced pets that have a microchip have a better chance of being reunited with their owners, so early placement is always a good idea.

What Do the Studies Show?

According to the American Veterinary Medical Association:

  • The British Small Animal Veterinary Association (BSAVA) maintains a database of adverse reactions to microchips. Since the database was started in 1996, over 4 million animals have been microchipped and only 391 adverse reactions have been reported. Of these reactions, migration of the microchip from its original implantation site had the highest numbers reported while tumor formation had much lower numbers.
  • There have been some old reports of mice and rats developing cancer with implanted microchips. However, the majority of them were being used for cancer studies when the tumors were found, and the rat and mice strains used in the studies were known to be more likely to develop cancer.
  • Tumors associated with microchips in two dogs and two cats have been reported, but in at least one dog and one cat, the tumor could not be directly linked to the microchip itself, and it is possible that it was caused by something else.

Are Microchips Safe?

Currently, cases of adverse reactions to microchips are only self-reported in the US. But using information reported in the UK, The AVMA says the risk to pets is very low and is far outweighed by the benefit of getting the pet back if lost. Therefore, the AVMA recommends microchips for safe permanent identification.

Do the Benefits Outweigh the Risks?

The answer is yes. But we will still list some of the potential risks.


  • Placing a microchip is a fast and easy process
  • It provides permanent identification that cannot fall off, be removed, or become impossible to read
  • Millions of pets have been microchipped without a significant amount of reported problems
  • They are relatively inexpensive and with the right scanner can be read all over the world
  • They are designed to last the life of your pet
  • And the most important: Thousands of pets have been reunited with their pet owners because of their registered microchips


  • Potential for injury or infection
  • Rare incidence of a microchip migrating from its original location
  • And as stated earlier, the very low incidence of reported tumor formation where the microchip was implanted

Other Things to Consider

  • Please register your pet's microchip with a current phone number and address. This is the only way you and your pet can be reunited if they are lost.
  • Make sure your pet's microchip is placed by a veterinarian. August 15th is "Check the Chip Day" so use this time to visit your veterinarian and make sure your pet's microchip is still working properly. This is also a great time to update any relevant information.


"What Are The Advantages Of Microchips? "Petfinder". Petfinder, 2020,