Comparison of bacterial culture, histopathology, and immunohistochemistry for the diagnosis of Johne's disease in culled dairy cows.

Paired samples of formalin-fixed, paraffin-embedded ileum and lymph node from 204 culled dairy cows were investigated for evidence of infection by Mycobacterium avium subsp. paratuberculosis. Of the samples, 151 were from animals that were tissue-culture positive for M.

The role of immunostimulation in the development of postweaning multisystemic wasting syndrome in pigs under field conditions.

We evaluated the effects of immunostimulation in the development of postweaning multisystemic wasting syndrome (PMWS) in 930 pigs 53 to 54 d old in a grower/finisher barn with a history of PMWS. The pigs were allocated to 5 treatment groups: 4 groups received a single intramuscular injection of RespiSure-ONE (a commercial Mycoplasma hyopneumoniae vaccine; n = 197), Emulsigen (an oil-based adjuvant; n = 172), Alhydrogel (an aluminum-hydroxide-based adjuvant; n = 172), or physiologic saline (n = 218); 1 group received no treatment (n = 171). Pigs affected by PMWS were found in all the groups.

Viremia during infectious salmon anemia virus infection of Atlantic salmon is associated with replicating virus in leucocytes.

In situ hybridization (ISH) was used to investigate the presence of viral mRNA in different fractions of blood cells of Atlantic salmon between 6 and 12 d following experimental infection with infectious salmon anemia virus (ISAV). Using a riboprobe targeting ISAV segment 7 mRNA, hybridization signals were observed only in leucocytes in buffy coat smears from samples collected from 8 to 12 d post-infection (dpi). None of the red blood cell smears from any sample showed ISH signal.

A retrospective study of sporadic bovine abortions, stillbirths, and neonatal abnormalities in Atlantic Canada, from 1990 to 2001.

In a retrospective study on 265 cases of sporadic bovine abortions, stillbirths, and neonatal deaths in Atlantic Canada (1990 to 2001), an etiological diagnosis was made in 117 cases (44.2%). The cases were divided into 2 groups: 234 abortions, and 31 stillbirths and neonatal deaths.

Correlation of virus replication in tissues with histologic lesions in Atlantic salmon experimentally infected with infectious salmon anemia virus.

We have studied the replication of virus in tissues and development of lesions associated with infectious salmon anemia virus (ISAV) infection in Atlantic salmon using in situ hybridization (ISH) with a riboprobe targeting ISAV RNA segment 7 messenger RNA. Fish were infected with three ISAV isolates (U5575-1, RPC-01-0593-1, Norway 810/9/99) and then euthanatized sequentially at 3, 6, 10, and 13 days postinoculation (dpi) and thereafter once a week for 8 weeks. Severe histopathologic lesions were observed in tissues from all groups beginning at the onset of mortality.