Zombie dogs was suggested just after I posted this thread. I dont see it working though, it wouldnt fit with the virus/story. A virus is pretty host specific. Wild dogs though would work as it could be those that are tamed. Once tamed you could throw a stick for them (flush them zombies out), you will have to keep feeding them though and in return they offer slight protection, advanced warnings in the form of a growl when zeds/survivors/bandits are near. Needs to be simple though, if too complex and it could turn into a tamagotchi shit fest. .