I think both, as each serve different purposes. On a forum, users have much more freedom to participate, write, share - whereas blogs are really for you to tell your stories and for us to comment on them.
I would keep both, and maybe use the blog to attract visitors to the forum, which will evolve naturally as a result.
Another thing you could consider is something I was going to do, but I'd be happy if you had the time/resources to do instead - and that is create a social network, using some free software.
I particularly like Elgg and would give it a spin:
[You must be registered and logged in to see this link.] But there are others too...
[You must be registered and logged in to see this link.]You may find that once you have something set up like that, it's something different so more likely to be used... e.g. there are plenty of popular Schnauzer forums and blogs already... even dog social networks - but no dedicated Schnauzer social networks for Schnauzer lovers!...
it's one to mill over anyway!