A federal judge has upheld Ohio's new restrictions on exotic animals after several owners sued the state over the law.

The judge in Columbus ruled Thursday the owners failed to prove constitutional rights were violated.

Seven owners had claimed the law forces them to join private associations with which they disagree and possibly give up their animals without compensation. They also challenged a requirement that animals be implanted with a microchip, which would allow the creatures to be identified if they get lost or escape.

State lawmakers passed the tougher restrictions after a suicidal owner released dozens of creatures from his farm in last year in Zanesville, Muskingum County.

Ohio officials have defended the law as a common sense measure to address the growing public safety problem of private ownership of exotic animals.