Firefighters at Sky Valley Fire in rural Snohomish County, Washington, used the opioid-overdose reversal drug naloxone to revive six puppies that officials believe ingested or inhaled fentanyl, Battalion Chief Brandon Vargas said Tuesday. The animals recovered and will be available for adoption within about a week — and some firefighters who treated them have expressed interest in giving them a permanent home.

The incident has prompted an animal cruelty and neglect investigation, authorities said. The Everett shelter housing the puppies has been overwhelmed with adoption requests, and officials asked the public to stop calling with inquiries about the animals.

Firefighters at Sky Valley Fire station in rural Snohomish County used the opioid-overdose reversal drug naloxone to save six puppies that officials believe were exposed to fentanyl, Battalion Chief Brandon Vargas said Tuesday.

Two people dropped off three of the sickened puppies at the station on Sunday. Sky Valley Fire is located about an hour’s drive northeast of Seattle. Officials believe the animals either breathed or ate fentanyl.

Firefighters sprayed naloxone into the puppies’ noses, administered oxygen, and performed CPR. The treatment worked quickly. “It wasn’t long before their tails started wagging,” Vargas said.

Snohomish County sheriff’s deputies later tracked down the two people who had dropped off the animals and found three more puppies that also needed treatment.

An animal cruelty or neglect investigation is underway, authorities said. The pair told authorities they had been caring for the puppies temporarily.

All six animals now have a clean bill of health but are being held in quarantine for approximately one more week before they can be placed for adoption, said David Byrd, manager of Snohomish County Animal Services. The Everett shelter overseeing their care has received so many adoption inquiries that officials asked the public to stop calling with questions about the animals.

Fentanyl and other synthetic opioids have been linked to accidental animal exposures in multiple states in recent years, with some pets successfully revived using the same naloxone protocols applied here.

Some of the firefighters who treated the puppies may be among their eventual adopters. “We definitely have some personnel that are interested in wanting to adopt those,” Vargas said.