[pyrnet] Help, losing hair!

[Caren Litvanyi <litvanyi@synack.net>]

About 8 weeks ago we adopted our Pyrenees girl from the humane society.
I noticed she was shedding a lot more lately, so I got the brushes out
tonight to work on her.  Oh no!  The hair on the side of her back legs
(upper) came out in big clumps, leaving only short fuzzy hair!  I brushed
the rest of her as best I could, and although a lot more than usual came
out, nowhere on her was as bad as her back legs.  I remembered someone
else wrote in asking a similar question - was there ever an answer what 
could be causing this?

I will make a vet appointment for her tomorrow, but I am panicking!
When we adopted her, she had just had a single puppy (a sort of accident
of a previous owner - long bad story), which was taken away from her
and given to another nursing pyrenees.  She was then spayed.  Could
sudden hormone changes cause this?

She was somewhat underweight when we got her, the vet thought she should
gain about 15 pounds (she is 1 1/2 years old).  Maybe we are feeding her
too rich a diet?  We are doing Flint River Ranch kibble with a little less
than a pound of raw beef mixed in per day.

Could she be allergic to cats?  She is in the same part of the country she
has been in for a while, so I doubt it's anything outside.  But I think our
cats are a new factor.

She is not scratching or biting or looking in any way disturbed by it.
My boyfriend thinks it is just stress from all the changes.  We took
her on a long car ride this weekend which sort of stressed her out, too.

The only other thing I can think of is she has gone from being a mostly
outdoor dog to being a 1/3 out, 2/3 in dog with us.  Too warm for her?

I am so worried!  She is very shy and we having been trying to take good
care of her and give her a good home.  What could be wrong?  She was
checked over moderately thoroughly by two vets on separate occasions when
we got her, and they thought other than underweight she was pretty healthy.
She looks bright and happy.  We live in Colorado where pests are less of
a problem also, so I don't think that's it.

Well, sorry for the long note - any suggestions are appreciated!
Thanks,
Caren and Kea