Does it mean he's obsessed, blind or dumb?, we wonder as he belts off towards a small dog (or sometimes distant large dog) - avoiding the inconvenient truth, as is our parental privilege.
Real rabbits, identifies correctly (often with our proactive assistance), our whippet chases at startling speed, blind to the world, ears back, long neck horizontal and wide smile. It's majestic. But rare.
And on occasions when he actually realises a dog approaches Frank does not belt. He advances with prances or runs away.
If I'm jogging he more often loops around bigger hounds I pass. He's an undeniable whimp or a docile playmate. Not an obsessive, fearless hunter.
With this latest development however, mid sprint realisation inevitably dawns and he slows to a prance or, much more hilariously, scampers full circle and whizzes back past us for cover.
Fuck me Dad. Did you see that rabbit turn into a Great Dane?!