The Nation has noted a Department of Justice estimate of 10,000 dogs per year killed by police. Last year, Reason dug up records showing that two Detroit police officers had killed 100 dogs between them over the course of their careers. And Reason obtained the best available data on dog shootings from several major jurisdictions that maintain some records: A Justice Department official speculated in a 2012 interview with Police magazine that the number could be as high as 10,000 a year, calling it "an epidemic." That figure that is often repeated in media reports about dog shootings, but it's little more than a guess. A 2012 study by the National Canine Research Council estimated that half of all intentional police shootings involved dogs.
There are no reporting requirements, unlike for other use-of-force incidents. Considering the U.S. doesn't even accurately track how many humans are killed at the hands of cops every year, it's no surprise the picture is so murky when it comes to dogs.