When Andrew Sullivan’s Beagle, Dusty, passed away  a couple of weeks ago he wrote a very moving piece about her at that time. Now he is writing about how his other Beagle, Eddy, has responded  to this loss. Again, in a very touching, observant manner.
I certainly believe that dogs can grieve, as well as possessing the full range of emotional expression as we have—it just might be more difficult for us to translate theirs. As another post  on Sullivan's The Dish site noted:
A few years ago when Bark’s “founding” dog, Nellie (a Beagle/Border Collie mix) died, Lenny, our 14-year-old Terrier, went into a tailspin. I feared that he too would soon leave us, dying of a broken heart. Like Sullivan’s dog, he stopped eating and simply wouldn’t respond to my attempts at consoling. It didn’t take me long to realize that Lenny missed having a pack mate and there was little that a human substitute could do. So we quickly decided to get him, and us, another dog. That is when our rescue Pointer, Lola came into our lives, and turned out to be the magic pill for Len—not only did he perk up almost immediately, but he seemed to drop years in a blink. It wasn’t that he liked Lola  all that much, but she added a necessary foil for him to maneuver around. He had a new motivation to live and since Lola was more concerned with “environmental matters,” as is the wont of sporting dogs, he got to trail after her in those pursuits. He went on to live another 4 years, and passed  away in my arms at 18.
I’m sure that you too have experienced this, not just a dog grieving for the loss of another dog (or other family member), but how a new dog can provide just the right antidote to the “other” dog. Let me know your thoughts.