Niles refers to a Triple Crown winner living in the stable. It is probably safe to assume that the horse was Seattle Slew.
Niles' impulse to buy Agides for Martin, instead of just arranging for a nostalgic visit, would have cost him approximately $10,000 a year in upkeep around 1997. The horse was never mentioned again.
Since extra studio space was needed to accommodate the horse stable set, no scenes on the radio station set were made. This was different from the usual practice of confining shots at Nervosa to the back bookcase nook, or the patio, when extra set space is needed.
John Mahoney was several years younger than his character, Martin. He was 57 years old at the time of this episode.