If scanning was the standard for all veterinarians and shelters, the missing pet epidemic could be significantly reduced to a manageable problem; however, there is a lack of standardization.
Multiple microchip companies, multiple scanners, multiple frequencies in which they operate, multiple cataloging systems and multiple registration data bases.
No true universal scanner can read the broad range of microchips encountered by veterinarians and shelters when they receive missing pets so pets are seldom recovered. It has ultimately led to a lack of scanning for microchips altogether. It’s much easier for a veterinarians to assume that the person that brought the animal into the vet is the pet’s rightful owner. At least the pet didn’t wind up in a shelter.
Further... The Animal Welfare Act does not authorize the USDA-APHIS to regulate private pet ownership and concluded that it cannot mandate a national standard for pet microchips or scanners. There have been various attempts to petition this law by various factions and numerous initiatives to introduce new laws by other factions- for at least 13 years.
Why isn’t there a global standard?
There is in Canada and the EU; however, pet ownership is not regulated in the United States. This is why the potential of RFID and microchip technology is limited.