Microchipping – permanent identification of your cat

Stray dogs and cats are a big problem in many countries. According to the Humane Society, there are around 70 million stray animals in the US – only about 6-8 million cats and dogs enter America’s 3,500 shelters every year.

It is hard to calculate the emotional cost to both the owner and animal when a pet is lost. Many pet cats have access to a cat flap or similar, meaning it is easy to stray away from home or be stolen.

Collars with tags are useful but are easily mislaid by cats. Microchips are a more permanent solution, and are a quick and efficient way to reunite owners with their lost pets, even across international frontiers. Ear tattoos are another form of permanent identification, but these are now no longer widely used due to the easier alternative of microchips.

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Loose dogs and cats can wander over large distances. Unless the animal carries some permanent identification it is unlikely that anyone finding it will be able to contact the owners or know how to re-unite them. Animal shelters only have limited room and unless the owners come forward, the animal will likely be given a new home, or even eventually be put to sleep. The information stored on a microchip implant is held on a central database allowing owners to be quickly contacted. This saves time and distress for the owners and their pets, cuts down the numbers of strays in shelters and saves money for the organizations which look after them.

A registered microchip may help to determine who owns a particular animal should an ownership dispute arise. As cats are often free-roaming, and it is not uncommon for a pet cat to live/feed in more than one house, microchipping can be essential if arguments over the correct owner occur.

A microchip is a small tube about the size of a grain of rice that contains a unique 15 digit code (identification number); this number is registered on a national microchip database and should also be noted down on your pet’s vaccination record and/or passport or Animal Health Certificate. The chip is made of an inert material which means it has no power source and won’t be rejected by your pet’s body. To retrieve your pet’s identification number, a scanner is passed over its body. The scanner sends out a magnetic field, which picks up the 15-digit code imprinted on the chip, automatically appearing on the scanner’s screen. The person scanning the pet can then contact the microchip database and provide this code. The database providers can then notify the owner about the recovery of their animal via the owner’s registered contact details. Veterinarians, police, rescue centers and dog wardens will all have microchip scanners.

Microchips are injected under the skin at the base (scruff) of the neck with a wide-bore, sterile needle. Onceyour veterinarian or another qualified person has implanted the chip, it should remain in place due to its unique cap that prevents movement. However, it is not uncommon for them to move around a little under the skin, and so when an animal is scanned, it is usual practice to scan the whole body, not just the scruff.

As the code is permanently embedded on the chip, there is no risk of the code being tampered with or changed. Equally importantly, the 15-digit code gives more than enough capacity for every pet animal in the world to be given a unique number. In the unlikely event that the microchip may fail, and the identification number will be unreadable by a scanner, your veterinarian may need to insert a new one; the registration for both of these chips should then be maintained in case the original chip is picked up on a future scan.

There is some international agreement on microchip standards so that microchips implanted in one country should be readable in others. Where possible, ISO (International Organization for Standardization) Standard microchips meeting specification 11784 or Annex A to 11785 should be used. If you are planning to take your pet abroad you should inquire about the type of microchip being implanted in your pet. For example, some microchip companies in the United States do not use ISO standard chips, and compatibility between chips and readers may be an issue if your pet has been microchipped in this country. If the microchip does not conform to ISO standards, it may not be able to be read by a standard microchip reader in another country when the animal is checked at the time of travel. If your pet does not have an ISO microchip you should carry an appropriate microchip reader when traveling with your pet.

Dogs and cats can be fitted with a collar and address tag, but collars can easily become lost and the tags damaged. Cats may also get their collars caught when climbing trees or squeezing through tight gaps and there is a risk of strangulation, so a quick release feature is essential. For many years tattoos have also been used to identify an animal permanently. Still, this method has several disadvantages – the ink can fade and become unreadable, the animal must be given a general anesthetic to keep it still when applying the tattoo, and tattoos can also be altered by further tattooing. There is also a risk of errors when writing down any long number, and it may be difficult to print a long code on the skin of smaller animals. Pets traveling abroad may use tattoo identification instead of a microchip if the pet was tattooed before 3rd July 2011, the tattoo is legible and the pet was vaccinated against rabies after the tattoo was placed. A veterinarian must note this information in the pet’s passport or Animal Health Certificate as appropriate.

A veterinarian or suitable trained person should only implant microchips as injuries due to poor implantation techniques have been reported. Microchips can be inserted at any age. The microchip can be inserted without a general anesthetic. A local painkiller is likely unnecessary but speak to your veterinarian if you have concerns. Any pain is minor and short-lived, and the chip will stay under the skin surface for the rest of your pet’s life. Occasionally the insertion site may ooze a few drops of blood after insertion. The chip is sterile, and although there is a very slight risk of introducing infection, this could easily be treated. The chip can move under the skin away from the original site, but it can be read anywhere in your pet’s body if the chip stays intact. There have been documented cases of tumors associated with microchips. Still, the risk is considered very low compared to the millions of animals worldwide that have received microchips with no associated problems.

Once the microchip has been implanted and the owner details registered, the animal is permanently listed on a microchip database. Many microchip providers pre-register their microchips to one database provider. If an owner does not register their details, the company selling the chips might be able to trace the location of where the chip was implanted. These database companies will maintain contact details and registration information for other microchip database providers, so registration with multiple companies is unnecessary. The five main microchip companies in the US are PetLink, Home Again, AKC Reunite, 24 Petwatch, and AVID.

When an animal is found, its microchip is read with the scanner, and the number is checked on the database. This provides information on the owner, who can then be contacted and informed of their pet’s whereabouts. Keeping information up to date with the database in the event of moving home or changing phone numbers is very important. The microchip will be ineffective without the correct owner’s contact details. A very common problem with stray cats handed in is that they are microchipped, but the contact details are out of date, and so although it is known that the cat is owned and loved, it is difficult to reunite them with their owners.

For cats that go outdoors, using a “cat flap” to allow free access for the cat to go in and out of the house may be helpful for some owners. Pet doors are available with sensors that can be programmed to recognize one or more individual pets’ microchips to allow only these pets access to the house while preventing other animals from entering. Feeding stations with microchip readers are now available – the feeder has a cover that can be programmed to open only for the pet with the registered microchip. This can be useful for multi-pet households to prevent overfeeding or make it easier when one pet in the household needs a prescription diet or medication in its food to which other pets should not have access. In the future, it is also hoped that microchips might be able to improve the monitoring of disease, for example, microchips that will monitor blood sugar levels for diabetic pets to reduce the necessity of frequent blood sampling and costly veterinary visits.