Microchipping - permanent identification of your dog
In many countries, stray dogs and cats are a big problem, with lots of money each year rounding up and looking after them. The hardest part is the emotional cost to both the owner and the animal when a pet is lost.
Dogs are often walked off-lead, making it is easy for them to stray or be stolen. Even though collars and tags are commonly used, these easily slip off or get broken. Microchips are now a legal requirement for pets and are a more permanent solution, as well as a quick and efficient way to reunite owners with their lost pets locally, and even across international frontiers. Ear tattoos are another form of permanent identification, however, they are now no longer widely used and are being replaced by the easier alternative of microchips.
Why is it important to be able to identify a dog?
It is now a legal requirement for all dogs and cats over 8 weeks old to be microchipped and registered since the new law came into effect in April 2016 worldwide.
Stray dogs and cats that have owners are easily identified if they have microchips as their form of identification. This makes it easy to rehome them and reduce the stress in animal shelters for space and the need to euthanise (putting them down) unnecessarily as, from the central microchip database, the owners can easily be identified.
Microchipping or other permanent identification of dogs and cats is essential for the implementation of the Pet Travel Scheme (PETS). All pets travelling internationally need to be permanently identified to enable easy confirmation of the required anti-rabies vaccinations. The best method of identification is a microchip, as tattoos can sometimes be illegible.
What is a microchip?
A microchip is a small tube about the size of a grain of rice that contains a unique 15 digit code; this number is registered on a national microchip database and should also be noted down on the pet's vaccination record, passport and/or Animal Health Certificate.
The chip is made of an inert material (glass) which means it has no power source and cannot be rejected by a pet's body. Retrieval of the pet's identification number, a scanner is passed over its body. The scanner sends out a magnetic field that picks up the 15 digit code that is imprinted on the chip and shows it up automatically on the scanner's screen. The person who scans the pet can then contact the microchip database office and provide the 15 digit microchip number. The database providers then notify the owner about the discovery of their animal via the owner's registered contact details. Vets, police, rescue centres and dog wardens all have microchip scanners.
How is a microchip inserted?
Microchips are injected under the skin at the base (scruff) of the neck with a wide-bore, sterile needle. Once the chip has been implanted by a qualified person, it remains in place due to its special cap that prevents movement, however, it sometimes moves around a little under the skin as shown below in the x-rays. As such, when an animal is scanned it is good practice to scan the whole body, not just the scruff.
Is the microchipping system foolproof?
As the code is permanently embedded on the chip there is no risk of the code being tampered with or changed. Essentially, the 15 digit code gives more than enough capacity for every pet animal in the world to be identified. In the unlikely event that the microchip fails and the identification number is unreadable by a scanner, a new one may need to be inserted. The registration for both these chips is then maintained for future scans in case the original chip is picked up.
Internationally, there are agreements on microchip standards so that microchips implanted in one country are readable in others. It is advisable that ISO (International Standards Organisation) Standard compliant microchips meeting specification 11784/11785 are used as vets globally have readers for these chips. Any pet travelling abroad should be verified about the type of microchip that was implanted, otherwise, as a pet owner, you may have to carry an appropriate microchip reader when travelling with your pet.
Are there any risks involved in microchipping?
Microchips should only be implanted by a veterinary surgeon or suitably trained person as injuries due to poor implantation techniques can occur. Microchips can be inserted at any age, but by law, puppies must now have a registered chip before 8 weeks, so are usually done while still with their mother before moving to new homes. The microchip can be inserted without a general anaesthetic. A local painkiller is likely unnecessary. Any pain is minor and short-lived, and the chip will stay under the skin surface for the rest of the 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 be treated easily.
Do microchips have any additional uses?
1. Microchips can also be used as a "doggie door" to allow the dog free access to the garden.
Pet doors are available that have sensors that can be programmed to recognise one or more individual pet's microchips in order to allow only certain pets access to the house while preventing others from entering.
2. Feeding stations with microchip readers are also available. The feeder has a cover with a sensor that can be programmed to open only for the pet with the registered microchip. This is useful for multi-pet households in order to prevent overfeeding or to 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.
3. 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 diabetics in order to reduce the necessity of frequent blood sampling and costly vet visits.
Reference
Arnaud, A., & Bellini, B. (2010, October). Full ISO 11784/11785 compliant RFID reader in a programmable analogue-digital, integrated circuit. In 2010 Argentine School of Micro-Nanoelectronics, Technology and Applications (EAMTA) (pp. 107-111). IEEE.
Hogewerf, P. H., & Pauw, R. (2005). The use of ICAR test procedures for electronic animal identification. Performance recording of animals-State of the art, 2004: Proceedings of the 34th Biennial Session of ICAR, Sousse, Tunisia, 113, 349.
Saputra, K., Kamelia, L., & Zaki, E. A. (2021, March). Integration of animal tracking and health monitoring systems. In IOP Conference Series: Materials Science and Engineering (Vol. 1098, No. 4, p. 042075). IOP Publishing.
Ingwersen, W. (2000). Standardization of microchip implantation sites. The Canadian Veterinary Journal, 41(3), 198.