their primary diet consists of feral cats, which are more along the size of an animal that is at serious risk. that includes small dogs. however, they will eat your labs if you give them the chance. you should keep them on a leash.
they seem to be all over the city at this point. i'm right in the middle of downtown, and just walked outside and saw tracks across my front lawn that seem intermediate in size between a wolf and a lab. my neighbour feeds the stray cats; i suspect there'll be at least one missing in the morning.