I only used 30kg as my lurcher is a bit smaller than most greys - and weighs 27kg - but I think a lot of that is muscle so perhaps she's rather heavy for her size! Hope all goes well even if you have a few problems initially.
Good luck! Bet DGreyhound gets the emetic injection and the charcoal. Should be fine after that, our "bloody dog" ate a tub of cocoa powder and lived to steal another day...Nicked my toast from the toaster this morning. Hope you're ok.