I have owned dogs all of my life from 100 lbs + to under 30 lbs. I have two 80 lbs + labradors now. One is old, moves slow and spends his time sleeping. The other is younger, active and looking to play constantly. I have a large fenced in yard (not good for fence jumpers though). Plenty of space for multiple dogs to run around. Our younger dog plays fetch, chasing his ball down our sloped back yard, so he gets plenty of exercise. I work from home and have flexibility in the mornings until the late afternoon (for walks). Nights are free for sitting, and we have our dogs inside at night. I have experience with lots of breeds and mixes as well.