Personally, for me, two dogs of my own is my limit. As for fosters, I can handle anywheres from two to six, depending on how much training and exercise they need. Currently I have five fosters.
As for cats...well, I know that there will always be a dog in my life, but I'm fine with not having a cat. Lillian's only three years old, so she's nowhere near old age yet, but I'm thinking when she goes, I won't be actively looking for another cat. Heck, I wasn't even looking for a cat when I ended up with my prissy princess in the first place, so...