I just overheard a park ranger talking about it last time i was in central park. The cp ranger office number is 212-360-1444 if you want to try and ask if it has been seen recently?

I would guess about 2-3 weeks ago there was a lost chiuauaha that matches that description reported to be running around in central park . I believe it was said to be by the Lake area? You could try calling the urban park rangers or asking some of the dog walkers in that area that could have seen it? Hope this helps and good luck!