Displaying and sorting items by last activity date

[tloder]

For my app, which tracks walks that people have taken shelter dogs on, I want to show a list of dogs sorted by the last walk date.

I have a dog table which has columns about the dog that are dynamic, and a walks table which is dynamically created when a new walk (activity) is performed. I can see a list of walks for each animal on the detail page, I just need to get the latest entry from that list.

I have been able to show the top walk date of the table, but the same entry shows up for each dog.

I would also like to show a conditional value on the walk date i.e. If more than one day make the text yellow, two days red

Thanks in advance for your help