Right now I have two dogs, five birds and 30-something bettas.

I think three dogs at the moment is ideal because of the small house we're in, and also because I work up to 12 hours a day 9 months of the year (but luckily there's always at least one person home). Once my doggy daycare is up and running, I can see myself easily handling four or five since they'll be coming with me to work.

At the moment, I think I could handle one more bird. Two of the tiels I rescued get extremely stressed out when I even come close to the cage, so they're happy in their big cage, and I'm happy letting the other three explore my room.

As for bettas, I have a system that can handle up to 96 bettas at a time and provide heated, filtered water constantly. Sooo.. seeing as how I do 30ish water changes a week already, I guess another 100 wouldn't be a problem. I don't intend to go that far anytime soon, but I could definitely handle it.