THEY'VE MOVED HIM," my dad reported the other night. "They've moved him into the hospital part of the nursing home. He's sharing a room now." But my grandfather's new living quarters aren't entirely bad, he added. "There's a curtain he can draw down the middle of the room. And we've already put up the pictures."

Ah yes, I thought, the pictures. For years the same two pictures have followed my grandfather as he's made his way through the graduated series of old-age habitats that are, I'm sure, familiar to many Americans: from the apartment-like spaciousness of "independent living" to the cramped environment of "personal care" to, now that he's 91 and has suffered another stroke, 10 square feet of hospital room proper. With each move the quantity of familiar furniture has dwindled but the pictures have remained: a portrait of his wife as a young woman and a photo of his two boys as boys. But there's one picture that's absent -- there is no photo of my grandfather's horse.

Horses, I should say, though the only one I knew was a chestnut saddlebred called Stonewall, so named in the early '60s, back when "Stonewall" was still an accepted thing for a Southerner to name his horse -- not out of belligerence or racial pride but simply because to a white man in southwest Virginia, it seemed appropriate for a creature so massive. There had been other horses, of course, and other names: As kids my brother and I liked to look through the old photos of all my grandfather's horses, inevitably posed with their ears forward and their legs showily stationed, and we loved to listen as my grandfather told us -- for example -- about the time, before a horse show, when he calmed a horse by getting it drunk.

My grandfather does not come from highbrow horsy-set people. His father owned a livery stable, and he grew up working there. As a result he learned not only to ride horses but to take care of them as if his livelihood depended on it, which it did. During the Depression he was obliged to leave college and come back to the stable, which, when horses became a vestigial part of our culture, turned into a family trucking business. But as long as I knew him he always had a horse, always knew horses and loved them so much that his palms would sweat whenever he watched the Kentucky Derby or any other race on TV.

Looking back, what is interesting to me is that my grandfather came from an era when men -- even as fathers and husbands -- were not given opportunities to nurture. It's true that at work, my grandfather was known for his harshness; so legendary was his temper that men would hide behind the wheels of their rigs to be invisible when he walked into the garage. Still, he must have had a nurturing streak, because on Saturdays he would pick up my brother and me and take us to Billy Guthrie's stable in Starkey, the rural crossroads where Stonewall was kept. There he would demonstrate how to put on the saddle and cinch tight the girth, how to brush a horse and scrape dirt from a horse's shoes. After we rode he would cool Stonewall down with a walk and give us sugar cubes to feed him. Thus cared for, Stonewall lived well into his twenties. Toward the end of his life he was on all sorts of painkillers, but even when there was no question of riding my grandfather would visit him daily, and groom him, and walk him, and once when my dad dropped by he found the horse stretched out in his stall and my grandfather stretched out as well, the two of them napping, side by side, in the hay. At last, though, the vet had to be called with his needle. I cannot imagine how my grandfather took that, the putting-down of the last horse he would ever own. I was, I believe, off at college at the time.

Because that's what families do. They go off to college. They spin out of orbit. And so my grandfather had this other life, this other love. There was his family and there was his horse, this creature that was reliable, and warm, and fenced, who waited for him and recognized him and always nickered, and came trotting over, when his car pulled up by the pasture's edge. He had something with his horses that was different from what he had with people, and whenever I visit him, and look around whatever euphemistically named nursing-home room he's currently occupying, I always feel sad that there is no photo of Stonewall or any other horse.

In thinking about old age, this is what frightens me the most. That in our later years the things we still have left -- and this is if we are lucky -- are the nuclear relationships and not the rich peripheral ones. Memories of spouses and children remain, but all the other encounters -- the passing friendships, the college roommates, the hilarious lunch partners, the cherished colleagues, the friendly neighbors, and yes, even the animals, the whole spectrum of relationships that make up our full and complicated human existence -- drop away as living space dwindles. That in the best of lives and the best of final chapters, there is little left to remind us of what we used to have and what we used to be, except the portrait of the spouse, the photos of the children, and the curtain down the middle of the room.

Liza Mundy's e-mail address is mundyl@washpost.com.