I can't comment on feeds, mostly because I got too enraged to learn that Mozilla did this thing where it overrode author stylesheets for feeds because they knew better or something... arg.
For the main url (all-available)
When using something like a screen reader, the tags you choose matter more: those assistive devices know what a header is, what a link is, what a table is, what a form is, what a list is... and can use those as navigation hooks etc. The benefit a definition list has is that it says "there's a key-value style relationship between what's in the dt and what's in the dd".
Something that occurred to me was the use of <strong> if you weren't going to use dt's or headers, however like using a 2-column table, it seems incorrect to use here. If CSS-off styling is that important to you, then a ul with strongs around the keys would keep things in one line, and still be a listing of pup stats. But I wouldn't like it nearly as much, semantically. Strong doesn't say "key", it just says "something's more important about this" which isn't quite correct here.
If cooper doesn't show up in this thread, then I'll say it: your site looks like a good candidate for something like [microformats or [url=http://en.wikipedia.org/wiki/RDFa]RDFa](http://microformats.org/about). You're displaying data in a regular format and it would be cool to let other devices (such as google for example) be able to use meta data to understand the type of data you're displaying.
*edit er, maybe not: you already have a lot of classitis going on already:
<div id="post-1349" class="hentry p1 post publish author-admin category-all-available category-female category-male category-urgent tag-kim comments-closed pings-closed y2010 m04 d05 h15 slug-puppies-or">
That's a lot of classes... microformats alone can add a lot more, plus spans everywhere. : (