A Dog's Life
Side quest Velen suggested level 5
From the journal
When Geralt saw a dog which was clearly someone's beloved pet surrounded by a pack of starving wolves, he could not help but interfere and save the poor animal's life. The wolves slain, he petted the dog to calm it and discovered there was a key sewn into its collar.
Geralt followed the dog to its owner's home. Sadly, there was no living soul within it.