Sadly, it's a feeling almost every pet owner can relate to.
On Tuesday, tennis champion Serena Williams gave an emotional farewell to Jackie, her beloved Jack Russell terrier, in a series of Instagram posts addressed to her "angel."
A photo posted by Serena Williams (@serenawilliams) on Nov 24, 2015 at 10:52am PST
"Today really is hard for me," wrote Williams. "My special friend [who] I got at 17 (2 weeks before I won my very first Grand Slam) left me today."
According to Williams, Jackie passed away Tuesday morning at the age of 16, having been with the tennis star for nearly half her life.