K9 Boomer and K9 Rip were both longtime members of the Salem County Sheriff's Office and died while working on Friday.
The sheriff's office says the K9s often traveled together in a vehicle outfitted for two police dogs. The office says that when their handler noticed something was wrong, the dogs were rushed to a Delaware emergency veterinary clinic, where they were pronounced dead.
The Salem County Prosecutor's Office is leading the investigation, and the cause of death has not been released. Prosecutors said the handler has been placed on leave during the investigation, and the sheriff's office is cooperating.
The deaths have shaken the local law enforcement community and prompted reactions from animal advocates and residents.
Sal Khan, president of the nonprofit Capital K9 Association, said police dogs play a vital role in public safety.
"They respond to calls and they help get guns, drugs, explosives, off the streets and make our communities safer," Khan said.
Khan's organization provides ballistic vests and heat alarm systems for K9s. He noted that heat exhaustion is the leading cause of death among police dogs, though officials have not determined whether that factor played a role in this case.
"It doesn't matter what the circumstances are; when you have the loss of life of K9 or a first responder, it's devastating," he said.
According to the sheriff's office, K9 Rip had been in service for two years as a patrol and narcotics detection dog, while K9 Boomer served for five years as a bomb detection dog.
In a statement, the sheriff's office said, "Their loyalty, service, and dedication to protecting the residents of Salem County will never be forgotten" and added, "We honor their lives with gratitude for all they gave and the service they performed alongside our officers in the countless ways they helped protect our community."
Residents also expressed grief and called for answers as the investigation continues.
"Sad because I love animals," said Pennsville resident Dave Heil. "A loss of a life is a loss of a life, whether it's human or animal."
Others emphasized the importance of honoring the animals' service.
"I have a dog at home myself and two birds, so I do love animals and I think they need the same care as any other human being," said Ana Carbajal of Deptford Township.