I believe everyone makes way too much of a big deal over Vincent. I think that he is put in these weird situations for a very logical reason and that people go crazy over them cause it's lost and nothing is ever simple.
Alright so in timeline on the island the first time we see Vincent is when Christian Tells him to go find my son. That was in of the podcasts or something. Whatever it was, that happened. He made Michael chase him into the jungle where he found sun and they almost kissed then he barked and stopped it. He's found bodies, he found Charlotte's Gps, all that kinda stuff.
So this is what I believe. If Jacob and his Nemesis can control people by touching them and controlling their destinies then why is it so hard to believe that they can control animals. Maybe Vincent is just being used by them at specific times to help main characters get to where they have to be. It seems pretty logical to me. Remember when the raft was leaving at the end of season 1, he jumped in the ocean and tried to swim just like any normal plain dog would do if they saw their owner leaving. I don't believe he is special, just at certain times can be used for assistance by the 2 god like characters.
I could be wrong, wouldn't be surprised if I am. Like I said this is lost. But it's how I feel up to now. It just annoys me when people post ridiculous things about the dog