Identification of Microchip Implantation Events for Dogs and Cats in the VetCompass Australia Database.

Simple Summary The implantation of a microchip can maximise an animal's chance of being returned to its owners, if separated, but is also a statutory requirement for companion animal owners in many jurisdictions across Australia. This study of the electronic patient records of 1000 randomly selected dogs and cats in the VetCompass Australia database revealed that the median age at microchip implantation was 74.4 days for individual dogs and 127.0 days for individual cats. Further exploration into the reasons for later microchipping in cats may be useful in aligning common practice with legislative requirements. In Australia, compulsory microchipping legislation requires that animals are microchipped before sale or prior to 3 months in the Australian Capital Territory, New South Wales, Queensland and Victoria, and by 6 months in Western Australia and Tasmania. Describing the implementation of microchipping in animals allows the data guardians to identify individual animals presenting to differing veterinary practices over their lifetimes, and to evaluate compliance with legislation. VetCompass Australia (VCA) collates electronic patient records from primary care veterinary practices into a database for epidemiological studies. VCA is the largest companion animal clinical data repository of its kind in Australia, and is therefore the ideal resource to analyse microchip data as a permanent unique identifier of an animal. The current study examined the free-text 'examination record' field in the electronic patient records of 1000 randomly selected dogs and cats in the VCA database. This field may allow identification of the date of microchip implantation, enabling comparison with other date fields in the database, such as date of birth. The study revealed that the median age at implantation for dogs presented as individual patients, rather than among litters, was 74.4 days, significantly lower than for cats (127.0 days, p = 0.003). Further exploration into reasons for later microchipping in cats may be useful in aligning common practice with legislative requirements.