We just got a cairn puppy to go with our mixed breed. Turns out the puppy is deaf. Won't be much of a watch dog, he sleeps real hard.
Time to get another dog!
Either a little yapper, or a deep voiced breed, the deaf one will key off the other.
Fierce, the cairn will take care of the problem once alerted.......
edit: i see you got another , train the cairn to key off the other dog ,...still very fierce once alerted