Daily KinzCare was an everyday activity in Webkinz World, located under My Pets. Pressing the "I LOVE MY WEBKINZ" button would award KinzCash and food for pets. If you do this everyday for a week, you have a chance to get an Exclusive Item. Daily KinzCare was replaced by the Family Score system when the site was updated to Webkinz X.
From the Kinzville Times:
To find it, visit the “My Pets” section of the Things to Do menu in Webkinz World. Just click the “Daily KinzCare” tab and you’ll see a button that says “I love my Webkinz.” Click the button, and you’ll get some KinzCash (ten the first day, and five more each for each day you visit in a week). You’ll also get some a free food! Click the “I love my Webkinz” button everyday for a week to fill up the heart and to get a chance to win a draw for an exclusive item!