How hard will it be for you when your Pet dies?

Our little cat, literally walked us home and straight through the front door. He’s the most amazing companion ever. We adopted a (unbeknowoist to us) very sick kitten a year ago, who I was immediately attached to and we’d only had her a week when she died in my arms. I felt devastated. Attachment disorders aside…

Why are we so attached to our animal companions? Does anyone else wonder what animals bring to our lives that make us grieve as deeply for them as when a human we loved passes?