Interesting discussion with a friend brought us to this. Would love some more info on it if anyone has any.

Probably makes some things a little looser just as it does in humans but I wouldn't have thought it fundamentally changes the structure of anything and most changes can be undone given diet and exercise afterwards.

a friend who breeds borzois swears that bitches look better after a litter, they fill out and 'settle into their angles'. However this happens anyway, often when zois are around 3 or 4, which is usually when they would have a litter so I'm not convinced.

I think it 'drops' them a bit - hope so as I am having mine measured for agility once she is off the pups and she is a marginal medium/large!

My bitch is definitely wider across her front after her first litter

Several of my friends say so, but I don't think Ellie looked any different structurally. But she's only one bitch of course. Now coat....... ;-)