The Horseracing Integrity and Safety Authority issued an updated list of enforcement deadlines for its rules and registration requirements Thursday. The required horseshoes and riding crop specifications will not be enforced until Aug. 1, a month later than previously announced, in order to ensure an adequate supply of both. Also delayed is the monitoring of racehorse vaccinations. The new vaccinations will be required by Jan. 1, 2023 to allow horses to be vaccinated with previously unrequired vaccines at times that do not interfere with training and racing schedules. Thursday's statement...