Recommendations for the Control of Salmonella Dublin in Dairy Calf and Heifer Raising Operations

Goals

  1. Keep Salmonella Dublin out

  2. Decisions when a source farm tests positive for Salmonella Dublin

    1. Manage Salmonella Dublin to prevent spread from animals from test positive farms to animals from test negative farms.

    2. Manage Salmonella Dublin to prevent spread between animals from test positive farms

    3. Prevent Salmonella Dublin from leaving facility back to home farms.

Keep Salmonella Dublin out

  1. Salmonella Dublin testing of source farms using:

    1. Salmonella Dublin Bulk Tank Milk ELISA on a quarterly basis (Consider testing for other pathogens as well, such as Mycoplasma).

    2. Random screening of individual animals coming into facility

      1. Sample 10-15 newly arrived calves on a quarterly basis per farm

      2. If under 3 months of age test could reflect either calf or maternal antibodies

      3. If 4 months of age and older test will detect calf antibodies and response to true exposure.

      4. This would not be used for culling decisions. Positive tests do not necessarily mean they are currently infected or carrier animals, but that they were exposed to Salmonella Dublin at some time.

  2. Perform necropsies and/or diagnostics on all deaths and abortions, including Salmonella Dublin cultures, to assure Salmonella Dublin has not been introduced.

    1. Calf deaths – include lung, liver, mesenteric lymph node tissues

    2. Abortions – Culture fetus, placenta and/or vaginal discharge (swab)

  3. Management of animals from test positive source farms:

    1. Exclude from facility

Decisions when a source farm tests positive for Salmonella Dublin

  1. Salmonella Dublin testing of source farms, so that source farm status is understood, using:
    1. Salmonella Dublin Bulk Tank Milk ELISA on a quarterly basis (Consider testing for other pathogens as well such as Mycoplasma).

    2. Random screening of individual animals coming into facility

      1. Sample 10-15 newly arrived calves on a quarterly basis per farm

      2. If under 3 months of age test could reflect either calf or maternal antibodies

      3. If 4 months of age and older test will detect calf antibodies and response to true exposure.

      4. This would not be used for culling decisions. Positive tests do not necessarily mean they are currently infected or carrier animals, but that they were exposed to Salmonella Dublin at some time.

  2. Perform necropsies and/or diagnostics on all deaths and abortions, including Salmonella Dublin cultures, to assure Salmonella Dublin has not been introduced.

    1. Calf deaths – include lung, liver, mesenteric lymph node tissues

    2. Abortions – Culture fetus, placenta and/or vaginal discharge (swab)

  3. Manage Salmonella Dublin to prevent spread from animals from test positive farms to animals from test negative farms:

    1. Segregate all animals from test positive source farms from test negative farms.

      1. Can group all animals from test positive farms together away from animals from test negative farms – in separate pens/groups with no physical contact.

        • Consider shared waterers; equipment; manure management; and feed/feed refusals These can all spread Salmonella from one group of animals to another.

        • Consider the possibility of aerosolization of Salmonella Dublin – Air movement; ventilation of barns; pressure washing, etc.

    2. Biosecurity – Refer to the NYSCHAP Critical Control Points to minimize spread around the premise.

    3. Combining animals from test positive farms with animals from test negative farms - Recommend doing this on a pen by pen basis after animals are 4 months of age or older.

      1. A pen could be considered for commingling with animals from test negative herds 8 weeks after no new animals have been introduced, proper biosecurity (see above) is in place and all animals from the positive source herd pen are test negative using the Salmonella Dublin ELISA blood test.

      2. Animals that test positive can either be removed from the pen to a separate pen and retest remaining animals in 8 weeks or leave all animals together and retest all animals in 8 week intervals until all are test negative.

  4. Manage Salmonella Dublin to prevent spread between animals from test positive farms:

    1. Good ventilation is critical.

    2. Group feeding is discouraged in pre-weaned calves due to its likelihood of transmission – nose to nose; shared nipples, etc.

    3. If calves are group fed – recommend small groups to minimize amount of spread.

  5. Reclassifying source farms from positive to negative:

    1. Need 4 consecutive negative Salmonella Dublin bulk tank milk ELISA tests on quarterly testing.

  6. Prevent Salmonella Dublin from leaving facility back to home farms?

    1. Difficult to offer high confidence levels that animals comingled from positive and negative source farms are Salmonella Dublin free without additional individual testing. Consider pen testing as described above.

    2. Recommend notification of positive tests of animals to source farms

    3. Recommend statement in agreement between source farm and calf/heifer raiser regarding contagious disease risks.

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