 Make sure they're microchipped and have ID tags on them at all times. That makes all the difference in the world. As animal control officials across the country see a 30% to 60% increase in the number of animals coming into shelters each year between July 4th and 6th. In fact, January 5th is one of the busiest days of the year at shelters, but only a small number of lost pets are ever returned to their owners. 30% to 60% are euthanized because they cannot be properly identified.