A couple of years ago I used to receive a lot of traffic via my category pages but now I don't receive as much, in the past year I've modified the category pages to canonical.
I have 15 genres for the category pages, other than the most recent sorting there is no sorting available for the users on the cat pages, a recent image link added can over time drop off to page 2 of the category page, for example
mysite.com/cat-page1.html = 100 image links per page with numbered page navigation, number of cat pages 1-23. New image link can drop off to page 2.
mysite.com/dog-page1.html = 100 image links per page with numbered page navigation, number of cat pages 1-53. New image link can drop off to page 2.
mysite.com/turtle-page1.html = 100 image links per page with numbered page navigation, number of cat pages 1-2. New image link can drop off to page 2.
Now on the first page (eg mysite.com/cat-page1.html) I've set this up to rel= canonical = mysite.com/cat-page1.html
One thing that I have noticed is the unique popup short description tooltips that I have on the image links only appears in google for the first pages of each category page, it seems to ignore the other pages. In view of this am I right in applying canonical ref or just treating it as normal pages.?
thanks