Space is all relative, I think. My mom has 4 dogs and a cat in a small 2 bedroom apartment. Granted 3 of the 4 dogs are under 20 lbs. but still, 4 dogs. I love it because I'm in the thought of "the more the merrier" and more opportunities to snuggle with one of them, whereas my hubby thinks that's too many.

If you've got the financial resources, and enough love in your heart for one more, then why not? You'll make room for him/her.