Pathological findings associated with naturally acquired porcine circovirus type 2 associated disease

Porcine circovirus type 2 (PCV2) is a novel virus of the Circoviridae family which is considered the cause of postweaning multisystemic wasting syndrome (PMWS). PCV2 has also been associated to a number of pathological conditions of pigs, including porcine dermatitis and nephropathy syndrome, reproductive failure, porcine respiratory disease complex, proliferative and necrotising pneumonia and congenital tremor type AII. Pathological studies have been used to describe and characterise PMWS and these emerging conditions associated with PCV2. The objective of this review is to concentrate on the gross, microscopic and ultrastructural pathology associated with natural cases of PCV2 associated disease, along with some speculations on the pathogenesis of naturally occurring PMWS.