Management practices associated with the bulk-milk prevalence of Staphylococcus aureus in Canadian dairy farms.

When designing mastitis-prevention and control programs, it is important to know the level of adoption of mastitis-prevention management practices and control programs and the herd-level prevalence of contagious mastitis pathogens. Our objectives were to estimate: (1) adoption of recommended mastitis-preventive management on Canadian dairy farms; (2) herd-level prevalence of contagious mastitis pathogens on Canadian dairy farms; and (3) associations of certain management practices with the isolation of Staphylococcus aureus from the bulk tank milk from Canadian dairy farms. In total, 226 farms participating in dairy herd improvement milk recording were randomly selected.

Prevalence of contagious mastitis pathogens in bulk tank milk in Prince Edward Island.

The purpose of this study was to 1) estimate the herd prevalence of contagious mastitis pathogens in bulk milk from Prince Edward Island (PEI) dairy farms, 2) determine the association between bulk milk culture results and mean bulk milk somatic cell count (BMSCC), and 3) investigate the agreement of repeated bulk milk cultures. Three consecutive bulk milk samples were obtained at weekly intervals from all 258 PEI dairy herds and were cultured using routine laboratory methods. Cumulative prevalence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp.

Update on antimicrobial susceptibilities of bacterial isolates from canine and feline otitis externa.

The in vitro susceptibility of a total of 1819 bacterial isolates from canine and 103 isolates from feline otitis externa cases to 13 antimicrobial drugs over a 5-year period was evaluated. Among topically used drugs, 90% of isolates were susceptible to gentamicin. Susceptibility of Pseudomonas aeruginosa to gentamicin was 85%, and to polymyxin B 100%.

Antibiotic resistance among enterotoxigenic Escherichia coli from piglets and calves with diarrhea.

In vitro resistance to 8 antimicrobials among enterotoxigenic Escherichia coli from piglets and calves over a 13-year period was evaluated. Least resistance occurred against ceftiofur for all, followed by apramycin and gentamicin for porcine and florfenicol for bovine isolates. No significant differences were found between the first 8 and last 5 years.