ACCT Philly has temporarily suspended adoptions and most intakes at its kennels as it continues to search for the cause of upper respiratory infections in a number of dogs, some leading to death.

“After consulting with national experts and other partners, ACCT Philly has been advised that the best chance of restoring health in its kennels will require a two-week shutdown of adoptions as well as the sheltering-in-place of dogs already in its kennels. During this time, ACCT Philly must avoid – as much as possible – any new intake into the general dog population,” shelter operators said in a statement issued Saturday.

For the next two weeks, no new owner-surrendered dogs will be accepted “unless the dog is a risk to public safety or is ill or suffering, and in both instances require euthanasia,” said ACCT Philly, which shelters 28,000 animals a year under contract with the city.

Assistance will be provided to dog owners who need to surrender their pets.

Testing has not identified any unusual pathogens, ACCT Philly said. But it was determined that “further exploration and precautionary measures were warranted due to some cases of unusually severe pneumonia that have led to the deaths of some of the affected dogs.”

Susan Russell, executive director of the agency, said she is aware of five deaths. The “dozens” of sick animals have been primarily newer intakes as opposed to dogs there longer term, Russell said.

Major viral infections such as distemper and canine influenza virus have not been ruled out, “but we still do not have the answers we need to definitively state what we are dealing with at this time,” ACCT Philly said.

During the weekend, limited space will be available away from the general population to hold stray dogs, with the goal of transferring them into rescues after 48 hours if no owner claims them.

ACCT Philly is seeking donations to help with the unexpected expenses resulting from the illness outbreak, and more fosters and volunteers for its own programs and for rescue partners to quickly and regularly move animals out of shelters and help prevent illnesses and potential euthanasia.