CYPRESS, Calif.—Four racehorses have died at Southland tracks in the last week, with two racing deaths at Los Alamitos, and one training death and one death listed as other at Santa Anita. Luca’s Ride, a 4-year-old gelding with two career races, was vanned off after Sunday’s second race at Los Alamitos and later died. He was owned by Ruben Garcia and trained by Jesus Nunez. Favorite Doc, a 3-year-old gelding with nine career starts and four first-place finishes, was vanned off after Saturday’s eighth race. He was owned by Junior’s Quarter Horses Inc. and trained by Monty Arrossa. Both deaths were listed as “non-musculoskeletal sudden death” by the California Horse Racing Board (CHRB). They are the third and fourth horses to die from a racing injury during the Cypress track’s current season, which began in December. However, five horses have died from training injuries at Los Alamitos this season, and …