A brief review of procedures and potential problems associated with the diagnosis of porcine reproductive and respiratory syndrome

Experience has shown that, for a number of reasons, a diagnosis of porcine reproductive and respiratory syndrome (PRRS) is sometimes difficult. In thi s review we discuss: (1)field observations and laboratory tests that are us eful in arriving at a definitive diagnosis; (2) the impact of so-called aty pical PRRS on diagnostic procedures in North America; (3) the means by whic h diagnostic problems can often be circumvented by appropriate sample selec tion; and (4) methods used for presumptive identification of PRRS virus str ains.