October 2017



Signalment (JPC #92-21908):  Piglet.

HISTORY:  This one-week-old crossbred piglet was from a litter that was born weak and within a few days exhibited respiratory distress (“thumping”).  The producer had farrowed six sows thus far in this grouping, and all six had litters with the above problems.  Most sows would eventually have one or two survivors per litter.

HISTOPATHOLOGIC DESCRIPTION:  Lung:  Diffusely alveolar septa are expanded up to 10X normal by numerous macrophages, lymphocytes, fewer viable and degenerate neutrophils and plasma cells, admixed with fibrin and edema.  Multifocally, alveolar lumina are variably expanded by an exudate composed of few previously described inflammatory cells, necrotic cellular debris, fibrin and edema that minimally extends into adjacent terminal bronchiole lumina.  Multifocally there is necrosis and loss of type I pneumocytes with alveoli being lined by cuboidal pneumocytes (type II pneumocyte hyperplasia and hypertrophy). Interlobular septa and perivascular connective tissue are mildly expanded by edema, fibrin and few macrophages, lymphocytes and plasma cells.

MORPHOLOGIC DIAGNOSIS:  Lung:  Pneumonia, interstitial, histiocytic and lymphocytic, diffuse, subacute, moderate, with type II pneumocyte hyperplasia, crossbreed, porcine.

ETIOLOGIC DIAGNOSIS:  Arteriviral pneumonia

CAUSE:  Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)

CONDITION:  Porcine Reproductive and Respiratory Syndrome

SYNONYMS:  Swine infertility and abortion syndrome; Porcine epidemic abortion and respiratory syndrome; Blue ear disease











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