I'm pretty open about the fact that I like dogs and do a lot with my dogs, but I don't tend to delve into just how much with most people (strangers, coworkers, etc.). But dogs are my main interest, and if people don't know that about me, then they don't know much about me. That said, I try really hard to not participate in dog conversations with people that are not also dog enthusiasts. Like my coworkers, for example. If dogs come up in the lunch room, I sit and listen and don't really chime in. Dog conversation with regular (ie: not crazy) people tends to frustrate me more than anything a lot of times, but I also know they're likely not going to take any of my advice and just think I'm a weirdo, so why bother unless directly asked. I won't give unsolicited dog advice unless it's truly warranted.
I post a lot of dog pictures on Facebook. Actually, that's pretty much all I do. But most of my Facebook friends are dog people, so at this point, I actually feel more weird about sharing family or other non-dog related things. I pretty much use Facebook as my dog people outlet haha. And I have custom settings so that sometimes when I know my non-dog friends probably don't need to see every photo I share, I can block my list of "non-dog friends" from seeing all of it.
But even among dog people, I'm less dog nerdy than they are usually. I'll never obsess over a sport I don't think. I'm mainly an active pet person with a lot of knowledge who likes to dabble in different activities and just enjoy my dog as a buddy in everything we might do. Be it walking, hiking, watching TV, playing fetch in a park or training. So when I'm with dog people who are even more obsessive about dogs than I am, I find the conversation interesting, but I often don't add anything in either as they know just as much and often more than I do. So, while I'm a dog person through and through (literally there is nothing that interests me more than dogs and dog stuff), there are times that even more crazy dog people make me feel like I'm not as much of a crazy dog person as I thought haha. But regardless, my closest friend is also a dog nerd and that's why we became friends. I think that for as much as I love dogs, it would be hard for me to be really good friends with someone who wasn't at least somewhat as much of a dog nerd as I am. And in order to become friends, I obviously made it clear from the beginning that I was pretty into dogs whether I meant to or not.