SIMI VALLEY, Calif. — California wildlife officials say five turkey vultures have died after they were poisoned with a euthanasia drug used by veterinarians.

The Department of Fish and Wildlife says the vultures were found dead in Simi Valley last month. Two other vultures were poisoned but survived.

The birds had eaten pentobarbital, which is used to kill dogs and cats, livestock and horses.

Turkey vultures are protected by federal and state law.

It’s unclear how the birds ingested the drug but officials say scavengers such as turkey vultures can be poisoned by eating the remains of euthanized animals that aren’t properly buried or cremated.

Authorities want people with livestock to be aware of the problem to prevent more poisonings.