Changes

==Pathology==

==Pathology==

Gross necropsy lesions are minimal in the uncomplicated respiratory form of PRRS, but interstitial pneumonitis is a consistent histopathologic finding. There are no gross or histopathologjc lesions noted in aborted or stillborn fetuses.

Gross necropsy lesions are minimal in the uncomplicated respiratory form of PRRS. Microscopically, interstitial pneumonia is the typical finding. There is a mononuclear infiltration of the alveolar walls with type 2 pneumonocyte proliferation, and necrotic debris and macrophages accumulate in the alveolar spaces. In lymph nodes, follicular hyperplasia and necrosis may be seen. Non-suppurative meningoencephalitis and choroiditis is commonly present, but severity is highly variable.

Microscopic lesions of the fetus

There are no gross lesions noted in aborted or stillborn fetuses, but histopathology inconsistently interstitial pneumonia, myocarditis anr pulmonary arteritis. However, these changes are not specific or diagnostic for PRRS.

and placenta include umbilical vasculitis, interstitial

pneumonia, myocarditis and pulmonary arteritis but are

inconsistent and not diagnostic for PRRS (Lager and

rate (Lowe et al., 2006).

 

==Control==

==Control==