The U.S. Department of Agriculture, which oversees the Animal Welfare Act, says it is "looking into" four incidents at the University of Michigan involving research animals.
The agency says that's not the same as a formal investigation.
The USDA is acting on a complaint by an animal rights group, SAEN (Stop Animal Exploitation NOW) which demands the maximum fine against the University for the deaths of several research animals, including the death of a baboon.
The baboon accidently strangled itself on a recreational device in its cage. Other incidents include a hamster that got loose and drowned in a floor drain, a rabbit that got loose after surgery and hurt itself, and a guinea pig that had to be euthanized after an emergency surgery by an improperly trained employee.
The incidents happened between 2011 and 2013.
Meanwhile, the University self-reported the incidents long ago to another agency, the National Institutes of Health.
The NIH has its own policy for the ethical treatment of animals in NIH-funded research.
NIH says the university took appropriate action -- in the case of the baboon, the same kind of recreational device was removed from other primates' cages -- and the cases have been closed.
A statement from the U-M says it will cooperate fully with the USDA.