Here you go some scketches based on your brief where you can ask for any changes or make any suggestions.
I know very well the Lusitano+s breed, including the Alter-do-Chão so I've drawed a very simple outlined head, with a friendly look, that can be reproduced even in small size like biz card and still ne recognizeable since it doesn't has small details and won't look cluttered but with a clean and modern look...
If any sounds promising, even after contest ends submissions are possible for the 1st ranked designer.
Kind regards,
Claudia