"He'd been with me for the major moments in my life, so it was tough when he wasn't," Baker said. "It's with a very heavy heart that I'm letting you know our wonderful Bob is no longer with us," Baker wrote in the original Instagram post. Baker described Bob as a constant, steadying presence throughout an eventful period of his life, both professionally and at home. Closing out the tribute, Baker reflected more broadly on the particular kind of grief that comes with losing a pet. Bob's death was not the first pet loss Baker has publicly mourned in recent years.