That number varies greatly from person to person. I know people with ten plus cats and dogs that do a WONDERFUL job and could probably take in more with no problem. I know people who could not handle a second dog or cat.

We currently have eight dogs - I had six and my husband had two when we married. At this time in my life, eight dogs is not too many. I do not want and will not get any more, but this is a good number for us. I work at home, so I'm here 24/7 with the dogs. Both of our sons are very into dogs, and give them a lot of attention as well. It works.

When I was actively doing rescue, I had usually between ten and fourteen dogs in the house all the time. I stopped doing rescue, because situations changed in my life which prohibited me from devoting the time required to the rescue dogs. Fourteen dogs would be far too many now, though it was fine then.

However, when I had a "real" job and was gone all day, and had a baby/toddler ... we had two dogs. Different situation, different number I could handle.

I think therein lies the true difference between responsible and irresponsible pet owner, between rescue and hoarder, etc. - knowing your limits. Those limits vary not only from person to person but from year to year with the same person.