May 14, 2015 1:53 PM EDT

An Oklahoma school apologized Wednesday after a video circulating on social media showed students holding up dead cats and making it look like they were dancing when they were supposed to be dissecting the specimens in a biology class.

The clip was filmed in fall 2013, but went viral this week after the animal rights group People for the Ethical Treatment of Animals (PETA) shared it on social media.

“We agree that animals should be treated and handled with respect and dignity, a standard that was not upheld in this instance,” Harding Charter Preparatory High School in Oklahoma City said in a statement on the school’s website.

Write to Olivia B. Waxman at

Read More From TIME

Related Stories