Laso's are not barkers as a breed, they do tend to be very quiet and some can be a little aloof. I work with German Shepard rescue in Scotland, we advise adopters that it takes up to 12 months for a dog to settle and trust you fully. Charley has had a lot happen in a short space of time, multiple vet visits, groomers, new home, new humans and cats. Be patient he is still adapting and by all means use treats you achieve more by rewarding and praising your dogs. My big boy was 15 months when we got him and had had a horrible time, it took him a long time to trust us and sometimes with rescue dogs you will only get them so far and have to accept their little foibles. Good luck with Charley and just keep praising and loving him.