Fine-needle aspiration and cytology as an antemortem method for evaluating injection-site lesions

Materials and methods: Two trials were conducted. In both, pigs were vaccinated with porcine circovirus type 2 vaccine at weaning and 17 days later. Seven days after the second vaccination, pigs with grossly visible injection-site lesions were selected (Trial 1, n = 40; Trial 2, n = 12). In Trial 1, pigs were manually restrained for the FNA procedure. In Trial 2, pigs were sedated and the FNA procedure was conducted using two different-sized hypodermic needles (18-gauge and 22-gauge). After the FNA procedure, pigs were euthanized and the injection-site lesions and lymph nodes dissected and submitted for histopathologic interpretation. All cytologic preparations were examined by a board-certified veterinary clinical pathologist.