The categorization of the forums isn't meant to define the topics of the forums themselves, nor is it meant to somehow be a meta-rule about what can and can't be talked about. It's simply a general rule of thumb, and it felt best to put "Pets" under "Social" at one time.

Of course you can talk about more serious topics in a social area; we talk about serious topics all the time socially in real-life... FWIW, I see plenty of 'serious' pet discussions in the "Pets" forum today.