An animal-rights watchdog group is stepping up its criticisms of the University of Utah after the death of three animals during laboratory procedures since 2015.

In a letter sent last week to the U.S. Department of Agriculture, Ohio-based Stop Animal Exploitation NOW!, or SAEN, encourages fines against the U. as penalty for regulatory violations that killed a rabbit, a marmoset and a macaque.

SAEN previously questioned the 2015 death of the macaque — a type of monkey common in laboratory research — which was burned and killed by a heater while under anesthesia.

But SAEN co-founder Michael Budkie said Monday that the additional deaths of a marmoset in August 2015 and a rabbit in August 2017 bolster the need for punitive action by the USDA, which regulates animal welfare in lab settings.

“This is no longer a single isolated incident,” Budkie said. “Negligence at the University of Utah has now killed three animals. That demonstrates a significant pattern.”

In a statement, U. spokeswoman Julie Kiefer confirmed Monday that the three animals had died as part of university procedures.

Kiefer said administrators have taken steps, including additional staff training and procedural changes, to minimize the risk of additional deaths.

“The University of Utah has respect and compassion for the animals in our care and has an entire team devoted to their welfare,” she said.

Kiefer also underscored the scientific and medical gains that stem from the use of laboratory animals.

“Research involving animals continues to play a crucial part in advancing our understanding of human health and disease and developing life-saving therapies and treatments,” she said.

According to USDA documents shared by SAEN, the marmoset died after a 10-hour procedure that was recommended to take between two and three hours to complete.

The rabbit, SAEN’s documents show, was placed under anesthesia and moved to a medical-imaging suite, where miscommunication and error led to the animal being deprived of oxygen for roughly four minutes.

Budkie said the university should face maximum fines for its alleged violations of the Animal Welfare Act — or $10,000 per infraction per animal. If the mistreatment continues, he said, the USDA could consider more severe penalties, including the closure of research facilities.

“That demonstrates a clear and long-term pattern of negligence that deserves a meaningful penalty,” he said. “Otherwise, there’s nothing to put pressure on the Unviersity of Utah to end these negligent deaths.”

The Tribune’s inquiries to the USDA’s regional offices were forwarded to the department’s Animal Plant Health Inspection Service, or APHIS. Those requests for comment and confirmation were not immediately returned.

Budkie said he had confirmed the USDA received his complaint, but he had not yet received a response related to any pending investigation or formal action.