It doesn't matter how often I do it, it's never enough. I go through periods when it's everyday and sometimes I just get lazy and only do it once every few days. Either way, it's never enough. Everything is hairy again about an hour after vac'ing. But I also don't brush them often enough so that's a big part of the hair problem here.
Once a week....but the only room that has carpet in it is the living room and Cinnamon only goes in there to look out the front door so she spends less than an hour a day there. The rest of the house has laminate and I sweep/damp mop with a microfiber mop at least once a day sometimes more if it is raining or she is blowing coat.
At least twice a day.....sometimes three. Especially my kitchen/mud room, because it's a dark gray slate and it shows EVERYTHING!!! My vacuum is permanently kept out in the open, cuz I'm always grabbing for it!!!