Ferrets and other animals
Ferrets can be very confident around larger animals such as dogs, but care should always be taken when introducing a ferret to an existing pet this size. Although a ferret bite can be painful a dog bite in retaliation can be fatal.
Ferrets are predators and will kill small pets such as rabbits, guinea pigs and birds if given the chance. The housing of both the ferrets and existing pets should be very secure and handling of ferrets should be kept away from these small species.
Please do also take into consideration that the constant smell of a predator can be very stressful for prey animals.