ANN ARBOR (AP) – The U.S. Department of Agriculture plans to review incidents involving animal research at University of Michigan, including the accidental strangulation of a baboon, officials said.

During the 2012-13 academic year a baboon was strangled when left unattended with a toy, a researcher performed an unapproved emergency surgery on a guinea pig and a hamster escaped from its cage and was found dead in a drain, The Ann Arbor News reported.

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University spokeswoman Kara Gavin said the Ann Arbor school reported the incidents to the National Institutes of Health because they violated the agency’s policy on the humane care and use of laboratory animals.

The university has a committee that meets to discuss the use and care of research animals, including any deaths, and then decides whether to forward information on an incident to NIH, which funds more than $500 million in research at the school each year, Gavin said.

After the death of the baboon, which was part of a vascular disease study, researchers reevaluated the toys used by primates and decided to stop using the version of the toy that killed the animal. The school went back to using a previous version of the toy, Gavin said.

The USDA is reviewing the incidents after animal rights group Stop Animal Exploitation Now filed a complaint in February. The university could face fines up to $40,000 if the USDA finds researchers mistreated the lab animals, the newspaper reported.

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“It’s very clear that these incidents are violations of the Animal Welfare Act,” said Michael Budkie, co-founder of the organization that filed the complaint. “You have laboratories that don’t seem to even be able to keep the animals alive (or) follow their own protocols.”

Tanya Espinosa with the USDA confirmed the complaint and said the department considering whether to investigate further.

“We are looking into this,” Espinosa said in an email. “If we determine there were Animal Welfare Act noncompliances we may decide to open an investigation at that time. There is no timeframe as we want to ensure we are as thorough as possible.”

The university houses 247,000 animals in research facilities, and about 320 are mammals other than rodents, the school said. The school reports between four to six incidents of non-compliance per year, and Gavin said it hasn’t been fined for animal mistreatment in at least 23 years.

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*Copyright 2014, the Associated Press.