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| There is currently no known effective treatment for PRRS. Non-steoidal anti-inflammatory drugs have been used in an attempt to reduce fever, and appetite stimulants to counteract inappetance and poor weight gain. However, these appear to have minimal benefit. Antibiotics may be used to counteract secondary bacterial infections. | | There is currently no known effective treatment for PRRS. Non-steoidal anti-inflammatory drugs have been used in an attempt to reduce fever, and appetite stimulants to counteract inappetance and poor weight gain. However, these appear to have minimal benefit. Antibiotics may be used to counteract secondary bacterial infections. |
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− | As treatment for PRRS is ineffective, prevention is very important. Bought-in stock and semen should be PRRS-free, and any animals joining the herd should be quantined on-site before being introduced to the cohort. Pigs should be tested on arrival to the unit, and again 45-60 days later before they join the main herd. | + | As treatment for PRRS is ineffective, prevention is very important. In herds where PRRS is not present, bought-in stock and semen should be PRRS-free, and any animals joining the herd should be quantined on-site before being introduced to the cohort. Pigs should be tested on arrival to the unit, and again 45-60 days later before they join the main herd. In herds where PRRS is endemic, breeding gilts may be exposed to adult sows before they becomre pregnant in order to induce immunity. Existing infection can also be elimitated by multisite production and segregated early weaning, but the long-term risk of reinfection is high. Complete depopulationn, disinfection and repopulation can also be successful, as can test-and-removal strategies. |
− | Elimination of existing infection by multisite production and segregated early weaning has also been described. While these strategies have had some success, the longterm risks of reinfection appear high. Prevention of viral spread by nursery depopulation has been described. This is successful when virus transmission is not occurring in the sow herd (usually 12-18 mo after initial outbreak), but the nurseries and growing/finishing pigs are still infected. All nursery pigs are removed from the farm to be finished elsewhere. The nurseries are then aggressively washed and disinfected and left empty for 7-14 days, after which they can be used normally. The technique has successfully eliminated PRRS virus from several herds, in which pigs have remained seronegative (for >1 yr) to market age, and production in the nurseries has improved, both in growth rate and mortality.
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− | Commercial vaccines, both modified live and killed, have been licensed and have been effective in controlling outbreaks and preventing economic losses.
| + | Both modified live and killed vaccines are available. These are effective in controlling outbreaks and preventing economic losses. |
− | Recently, eradication of PRRS has been demonstrated to be possible on an individual farm basis. Methods such as whole herd depopulation-repopulation, test and removal, and herd closure have been documented as effective methods for eliminating PRRS virus from endemically infected herds. Unfortunately, a number of eradication efforts have failed due to the introduction of new isolates through unidentifiable routes.
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