spaniel

Question
my spaniel has started showing her teeth, growling,and threatening to bite us when she has got onto either our sons or our beds. When she is downstairs shes very soft and comes for strokes but wont let us near her when she goes upstairs. As far as we know she hasn't been in contact with any male dogs so why the strange behavior?

Answer
I need to know a few things before I can answer this.
How old is this dog?  How much training has she had?

Doing that while on "your bed" is a sign of dominance.
The first thing to do is not allow her in those areas.
But you will have to address the basic problem which is that she's not clear on the pack order in your house.

Not to worry...this can be handled especially if there are no other signs of dominant behavior.  Everyone thinks cockers are these cute little bundles of fur but they are VERY dominant dogs.  She's trying you on and you're smart to get help "now" before it accelerates.

I do need to know what (precisely) commands she knows and how trained she is before offering suggestions.
Delores