1 dog.
Nothing else. I've realized through working in a dog daycare (and dog sitting on the side) for a little over 2yrs now that I have a hard time sharing attention. When I'm at work I focus on one dog for about 10 minutes and just rotate throughout the day. When I dog sit, having more than one dog to take care of just gives me mad amounts of anxiety. I can do it no problem, however it stresses me out because I feel like they aren't being completely fullfilled. I admire those who can manage a multi dog household, but still baffled as to how. I also have a huge favouritism problem and that's unfair as well. Heck, I have a favourite dog at the daycare I work at that is almost impeding me getting a dog because I love that mutt so dang much I worry about comparing my own, actual dog to him! We're bonded (he comes every day and I spend 6-8hrs with him) so it would cause an issue. LOL
Other pets, zero. I love my cat to death however I will not get another one. She's special and I love her, but I find cats to be a burden otherwise. I've have multiple other small animals before (degus, hamsters, budgies, snake, iguana) and find them to be a burden also. I love cats and other animals that I do not own, though. I enjoy interacting with them as long as they aren't a responsibility of mine.