BALTIMORE — An animal rights group has filed a federal complaint against Johns Hopkins University researchers over a lab experiment in which nine dogs had to be euthanized after spinal surgeries.

The Baltimore Sun reports that Stop Animal Exploitation Now wants the US Agriculture Department to impose fines of $10,000 per animal under the Animal Welfare Act.

The group says Hopkins told the National Institutes of Health that it ended the federally funded experiment to study gastrointestinal issues when some dogs suffered acute paralysis.

Hopkins spokeswoman Kim Hoppe said the program rigorously complies with animal welfare regulations, and that the remaining dogs were adopted.

Federal law requires animal testing of drugs for humans. The Sun reports that almost 800,000 animals other than mice and rats are used in research facilities each year.