I have a Samoyed bitch that preforms in that manner . She's a lovely gentle animal , timid really but if she gets scent of any vermin then her whole body language changes and she begins to stalk and pounce in a more cat like than dog like manner.
Here's a pic of the fox that inspects my beehives every dawn and dusk. It's a big section blow-up from my mobile phone so apologies for poor pic quality.
I have had two fox cubs curled up in the sunshine in my garden - beautiful. The vixen comes every night to the garden.
I leave the dead squirrels for them - good recycling units!