While external biosecurity focuses on exclusion – don’t let it in – internal biosecurity focuses on containment – don’t let it move, says Dave Wright, DVM, project coordinator for the porcine reproductive and respiratory syndrome (PRRS) regional control projects in Minnesota.

Internal biosecurity focuses on controlling virus movement from pig to pig, litter to litter, room to room and barn to barn.

Some pigs with the PRRS virus can remain persistently infected for 200 days or more. Since the virus can spread via blood, saliva, milk, urine, feces, semen and aerosol, remember these tips to reduce the risk of transferring the virus within your herd:

• Practice McREBEL (Management Changes to Reduce Exposure to Bacteria and Eliminate Losses). Limit cross- fostering to the first 24 hours after birth, keep piglets in the same farrowing room, and humanely euthanize sick and debilitated pigs that are unresponsive to treatment.

• Move pigs all-in, all-out by room.

• Wear gloves when handling piglets and change gloves between litters.

• Change needles between litters.

• Install a bench entry at each building for changing boots and coveralls, and wash hands prior to entry.

• On single site, farrow-to-finish farms, arrange chores so that movement is from high health areas to lower health areas. If bench entries are not feasible, provide a temporary foot wash and hand sanitizer at each door.

• Remember that fomites such as tools and syringes can carry virus. Leave dedicated tools and instruments in each building or sanitize prior to entry.

For a full evaluation of your biosecurity practices, conduct a PADRAP assessment (Production Animal Disease Risk Assessment Program). For instructions and information on PADRAP, visit www.padrap.org.