I have a question for those who breed rats on a big scale. As some may know i am in the process of building a big rat breeding "shed"(26'x26') and im thinking of ventilation. How much would one need to properly ventilate the rooom and how important is extreme ventilation?

I ask because i always heard rodent feces can get you really sick even with limited contact...
I used to do demo on old houses and we had to wear face masks around mouse droppings to stop from getting sick, how true is all this and is there a good chance of getting sick from it?