Should we call a behaviorist?

I'm a little worried about Murphy, our 2-year-old shelter rescue. We think he's mostly basenji, and we adopted him five months ago.

He's mischievous, but smart, and it's only recently that we've noticed some aggression in him. When we give him a rawhide bone, he growls loudly and sometimes snaps if we get close to him. I know this isn't abnormal behavior, but we're afraid it will lead to worse things. For instance, when we towel Murphy off after being outside in the rain, sometimes he does the growling/snapping thing, trying to bite our hands (he's never broken skin). He's also started barking or growling low at us for attention or to get us to interact with him. This is a recent thing--he used to be practically barkless.

Murph is a good dog, and doesn't protest AT ALL when he sneaks up on the bed and we lift him off, or when we handle his feet, or give him a bath. He isn't allowed on any furniture, doesn't sleep with us, and we always eat something ourselves before we feed him. But I'm afraid he understands that we're a bit frightened when he growls and tries to "bite" us, and that this is going to escalate. He hasn't been to obedience school with us, but at this point, I'm wondering if it makes more sense to call our vet and get the name of a behaviorist (let's hope that isn't too pricy...).

Any advice is welcome! We love Murph so much and want him to be a good dog!! :(

A behaviorist may be a good idea, but I would also consider obedience as well, maybe first. We are going through some similar issues with our new rescue, and we are starting classes this weekend. I went throught classes with our Toy Fox Terrier, Chester 4 years ago and I think it made all the difference. Sometimes too, nipping starts out as play and does escalate, sometimes it doesn't. Chester still barks and growls to get us to play with him, but when we tell him to stop, he does. I personally would get a handle on it asap. Good luck and let us know how things go. :)