Would like to know the name of the sound a dog makes which is a hight
pitched, low decibel sound, NOT A WHINE, generally made when the dog
is anxious, expectant, bored (don't know all the occasions, but is not
a hostile sound).  It's more of a high pitched whistle which comes
from the muzzle (nose) area.  I thought it was called "keening" but
have been unable to find a verification of that.  The sound may, in
fact, be called keening; if so I would like that verified.  Putting
"dog sounds", "keening", "dog keening" in the Google search engine
buried me with hits, but on each, I quit reading after the 2nd page;
so am not sure the answer was not there.

http://www.puppydogweb.com/caninebreeds/basenji.htm

They use the word keening as you describe.  1st paragraph.

Keening is definitely a description of a certain sort of whistling
sound that dogs make. As I understand keening, it may indicate that
the dog feels uneasy, frustrated, or frightened. A dog who makes this
sound is not a happy dog.

Many citations of dogs & hounds keening may be found with this search string:

://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=dog+OR+hound+%22high+keening+sound

I'm not sure that Pink Freud's reply is necessarily accurate though I
have to admit I can't do any better. As he says keening is the sound
of a dog that is unhappy in some way but I THINK the sound you mean
isn't keening but the sound of sheer excitment.

My Dobermann does this regularly when she is excited about something
and it either sounds like a kettle boiling or like someone has tied
her mouth shut and is then squeezing her tightly! It's basically a
good sound - so excited that she just can't keep quiet.

Having said all that I can't find any reference to what the noise
would actually be called anywhere so I'm afraid I can't help any more
than to give the fuller description of the noise that I THINK you are
after.