Why should I microchip my cat? They wear a collar, or they don't leave the house.
Microchipping is probably the thing most likely to return your cat to you if they ever get lost. Cats lose collars quite easily, and if you think your cat will never get outside as an indoor only cat, you have a very high likelihood of being mistaken. Windows get left open with loose screens, or you may have visitors going in and out of your house without noticing your cat slipping out the door.
A microchip is a small electronic device that is about the size of a grain of rice. It is implanted under your cat's skin in the area of the shoulder blades using a syringe with a 14 gauge needle. It causes no disease, and it is completely inert. Over time scar tissue forms around it and your cat won't even know it is there. But, it contains an alphanumeric number that is unique to your cat, and to the company that makes it.
After the microchip is implanted, you will fill out paperwork that registers your cat's number with your personal contact information. You can change this information at any time simply by contacting the company that made the chip and that maintains the registry.
If your cat is picked up by animal control, turned into an animal shelter, or even taken into a veterinary clinic as a stray they will be scanned to check for a microchip. If your cat is chipped, then the scanner will find it and notify the person scanning that there is a chip present, and the number assigned to it. Based on the number, that person will then contact the company registry, read them the chip number, and get your contact information.
Now, this system isn't perfect. If your cat is found but never taken in as a stray to a vet or an animal shelter, then the person who found your cat may never know that there is a microchip implanted. If the chip for any reason migrates via gravity to an area on your cat's belly or in a leg, there is a chance that the person scanning your cat won't find the chip, although the chips are designed to try and prevent migration. The chip also has no GPS capability. Maybe someday, but not yet. So, you cannot find your cat using radiofrequencies or a GPS locator. But when you consider how easy it is to lose a collar, a microchip is better than nothing, and it requires no maintenance whatsoever.
There are two types of chips available in the United States. The standard 125 kHz chip is the chip most commonly used in theUS. However, the ISO chip which is 134 kHz and which is used in most European countries is starting to be used in theUS. If you plan on doing any kind of international traveling with your cat, even if it is just toCanada, we recommend implanting the ISO chip. However, if you never intend to take your cat out of theUnited States, then we recommend the standard 125 kHz chip. The reason for this? Almost every animal shelter and veterinarian in the country has a scanner that will scan for the standard 125 kHz chips. However since ISO chips are just starting to be used, a high percentage of animal shelters and veterinary clinics do not have the newer scanners required to be able to scan for the ISO chips.
A study was published in 2009 citing the chance of a cat being returned to their home with a microchip versus no microchip. Cats that did not have a microchip only had a 1.8% chance of being found and returning home, whereas cats that were microchipped had a 38.5% chance of getting back home. That is a significantly higher chance of getting your lost cat back. For the cost of a microchip, it is more than worth it.