J. A. House and C. A. House

“ Lesions in local lymph nodes are not extensive, and the virus is not readily isolated from them. Secondary lesions are believed to result exclusively from the spread of the virus from an existing lesion, not by a cellassociated viremia as in most other poxvirus infections. The virus has not been recovered from the blood (Kasza and Griesemer 1962; Shope 1940) , but this may be due to the fact that the SwPV is difficult to isolate, especially when in low concentrations. Viremia must occur, as evidenced by congenital infection in piglets. ”

“ Young animals are more severely affected than adults. Suckling piglets may have lesions in the perioral epithelium or a generalized disease with lesions all over the body. Lesions are more prominent on the hairless parts of the skin. Mechanical transmission by pig lice results in lesions on the lower parts of the body, including the udder and vulva. Transmission by flies and mosquitoes is less common and may result in lesions on the dorsal parts of the body, including the snout and ears. Sporadic congenital infection has been reported (Borst et al. 1990; Paton et al. 1990) . ”

“ Swine do not develop high levels of neutralizing antibody (Shope 1940; Kasza et al. 1960) , and negative results on the virus neutralization test should not be interpreted as the absence of SwPV infection.
TREATMENT There is no known treatment for SwP, although antibiotics may diminish the complications caused by infection with secondary bacteria. Affected animals should be isolated. Ectoparasites should be controlled by the use of licensed insecticides, and the premises should be aggressively cleaned and disinfected. ”