SIOUX CITY, Iowa (AP) — Fewer people in Sioux City are reporting dog bites in the wake of a crackdown on pit bulls and vicious dogs. The Sioux City Journal reports that officers responded to 37 percent fewer dog-bite complaints last year than they did in 2007, the year before the city banned pit bulls.

The ban included an exception for owners who registered their pit bulls, but no new pit bulls were allowed. More than 550 were registered before the April 2009 deadline. That number has since declined to 163. Dog experts say it’s not clear whether the decline in reported bites is due to the city’s ban or other factors, such as bites that go unreported.

Pit bull owners say the ban unfairly targets one breed.