Birdstone was declared out of Saturday's Blue Grass Stakes (gr. I) after tests showed an elevated white cell count.The scratch was another blow for trainer Nick Zito, who earlier in the week had Eurosilver sent to the sidelines with an infection that knocked him out of Kentucky Derby (gr. I) consideration. Eurosilver was being pointed to the Blue Grass.Birdstone, by Grindstone, is owned by his breeder, Marylou Whitney. He won two of three starts last year at two, including the Champagne Stakes (gr. I). This year, he won his first start, an allowance race at Gulfstream, before finishing fifth as the favorite in the Lane's End Stakes (gr. II) March 20 at Turfway Park.Birdstone was listed at 8-1 for the Blue Grass. A field of eight will now go postward including another Zito-trainee, The Cliff's Edge.