Farm-based control measures for caseous lymphadenitis in small ruminants: Offering a choice to the producer

Farm-based control measures for caseous lymphadenitis in small ruminants: Offering a choice to the producer

Summary

This project identified farms at risk of caseous lymphadenitis (CL) in sheep. Thirteen farms and approximately 400 sheep have been tested for CL; most of these sheep have been tested twice to verify serostatus over a 2 month period. All testing has been done by either the PI (Dr. Lichtenwalner) or collaborating veterinarians (Dr. Becky Myers-Law, Dr. Megan Flanagan, Dr. Don McLean, or Dr. Tammy Doughty). At each visit, the farmer cooperated with handling and identifying sheep, and also discussed biosecurity measures to avoid or contain CL on their farm. On several farms, CL abscess treatment was demonstrated and discussed. These visits also allowed discussion of other sheep health management issues, and helped to forge professional relationships with the producers. All serum results have been delivered to the producers and vets, and discussions of outcomes are now being conducted, along with biosecurity surveys and discussions with producers.

Objectives/Performance Targets

Farmer interactions:
13 (original goal was 4) farms have been identified and each has signed a permission form for UMaine. Each has agreed to allow blood testing of sheep twice, to keep adequate records to allow identification of sheep, sheep location, treatments and culling, and to allow investigators access to those records. One farm was unable to allow the second blood test, after several requests, due to lambing schedules. Vet stipends have been billed, and payment using the grant funds is in progress.

Serologic testing: All testing has been done by agreement with Washington State University. Duplicate samples are stored at the University of Maine for test development at the PI lab. All test results have been reported to the collaborating farmers and their vets.

Treatments:
Treatments/vaccinations used at participating farms are being recorded. These records will be used to create the “decision tree” for farmers.

Accomplishments/Milestones

The IACUC approval, agreement forms and schedules were developed during May to June 2012. Visits to farms occurred during June to December 2012, and lab tests were conducted from June to December, 2012. New test development and validation will take place during January to April 2012.

Impacts and Contributions/Outcomes

An interim report was presented at the Maine Sheep Breeders Association annual meeting in October 2012. Only a few farms were completely negative for CL during the study. Of the other farms, a new introduction was detected early in one, allowing culling/quarantine choices by the producer in a high-value breeding operation. One producer was unaware of the presence of a large number of seropositive animals in his “open” flock. Two farms with high numbers of CL-positive animals were able to implement new biosecurity plans; one of these farms will be followed beyond the scope of this project to ensure CL status. Other reports will be made available as the project nears completion in spring 2013.

Collaborators: