A new study by Penn Medicine and Penn Vet has uncovered a 41 percent increase in opioids prescribed for pets over a 10-year period, but only a 13 percent bump in the number of pet hospital visits.

The prescription spike could have been driven by the complex care offered at a veterinary hospital like Penn’s, as well as the desire to spare beloved pets from pain, according to the study authors.

On the other hand, it might also mean all those prescriptions didn’t go to Fido and Fluffy.

“As we are seeing the opioid epidemic press on, we are identifying other avenues of possible human consumption and misuse,” said senior study author Jeanmarie Perrone, director of medical toxicology at Penn Medicine. “Even where the increase in prescribed veterinary opioids is well intended by the veterinarian, it can mean an increased chance of leftover pills being misused later by household members.”

In what Penn called the first study of its kind, the researchers examined pharmacy records at Penn Vet’s Ryan Hospital from 2007 to 2017. They reviewed the patterns for the four opioids prescribed or dispensed to small animals – tramadol, hydrocodone, codeine tablets, and fentanyl patches. Dogs comprised 73 percent of the intended consumers, nearly 23 percent were cats, and the rest were mainly rabbits, snakes and birds.

“We found that the increased quantity of opioids prescribed by our hospital was not due to increased patient volume alone,” said study author Dana Clarke, an assistant professor at the vet school. “It’s likely our goal of ensuring our patients are pain-free post-operatively, particularly those requiring complex and invasive procedures, has driven our increased prescribing practices during this period.”

However, Clarke added, “we don’t know the potential or extent of prescription diversion from animals to humans, and what impact this could have on the human opioid crisis.”

The new study, published Friday in the journal JAMA Network Open, is hardly the first airing of the potential for abuse of pet meds – or, for that matter, abuse of pets to get drugs.

In August, U.S. Food and Drug Administration Commissioner Scott Gottlieb issued a statement acknowledging the potential for veterinary-prescribed opioids “to lead to addiction, abuse and overdose in humans who may divert them for their own use.”

He called on veterinarians to be responsible in their prescribing of opioids, including using alternative medications when possible, educating pet owners about safe opioid storage and disposal, and following federal and local prescribing regulations, as well as professional standards set by the American Veterinary Medical Association.

Shortly before Gottlieb’s message, researchers with the Center for Health, Work and Environment at the University of Colorado and an area medical consortium published the results of a survey in which 13 percent of the vets queried said they believed they knew of an owner who purposely injured a pet, made it ill or made the animal appear to be ill to get opioids. In one widely reported 2014 case, a woman in Kentucky was arrested after she allegedly cut her golden retriever on multiple occasions so she could get pain medication.

Concern about veterinarian-prescribed opioids has already resulted in some states creating new medication restrictions. In Pennsylvania, state legislators are looking at this issue with the state’s Veterinary Medical Association. Other states have taken steps like limiting the amount of opioids that can be prescribed to a single animal, requiring background checks on owners’ opioid prescription histories, or having vets report their prescriptions to a central database, they said.

At Penn Vet, there are efforts underway to reduce opioids in favor of local anesthetics after surgeries, creating opioid administration guides, and monitoring patients that need long-term opioid use, such as dogs with chronic coughing that requires hydrocodone.

Also needed, said the researchers, is additional study to determine the scope of diversion of veterinary opioids.