Assessment of exposure to influenza A viruses in pigs between weaning and market age.

Influenza A viruses (IAVs) are common causes of respiratory infection in pigs. The objective of this study was to characterize the circulation of IAVs between weaning and market age on the basis of development of antibody response and molecular epidemiology of detected viruses. Two batches of weaned pigs were followed in the nursery and finisher barns with a sample of 81 and 75 pigs.

Longitudinal study of influenza A virus circulation in a nursery swine barn.

Commercial production of swine often involves raising animals in large groups through the use of multi-stage production systems. In such systems, pigs can experience different degrees of contact with animals of the same or different ages. Population size and degree of contact can greatly influence transmission of endemic pathogens, including influenza A virus (IAV).

Molecular characterization of H3N2 influenza A viruses isolated from Ontario swine in 2011 and 2012.

Background: Data about molecular diversity of commonly circulating type A influenza viruses in Ontario swine are scarce. Yet, this information is essential for surveillance of animal and public health, vaccine updates, and for understanding virus evolution and its large-scale spread.

Methods: The study population consisted of 21 swine herds with clinical problems due to respiratory disease.

Udder health in dairy cattle infected with Neospora caninum.

Blood samples were collected from 3449 cows on 57 representative Ontario dairy herds during the summer of 1998 and analysed for antibody to Neospora caninum using an ELISA. Forty-eight herds (2742 cattle) contained at least one N. caninum-seropositive animal.

Fatal trichuris spp. infection in a Holstein heifer persistently infected with bovine viral diarrhea virus.

Whipworms (Trichuris spp.) were identified in the colon of a recently purchased, 10-month-old dairy heifer that died suddenly. A skin test was positive for bovine viral diarrhea virus (BVDV).