Johne's Disease

Direct Fecal PCR Mycobacterium paratuberculosis

The Iowa State University Veterinary Diagnostic Laboratory is now offering qualitative direct fecal PCR testing for the detection of Mycobacterium avium var paratuberculosis DNA in bovine feces.  Results are available in 3-5 days compared with the eight weeks required for liquid fecal culture testing. Sensitivity for the direct PCR is comparable to the culture system for high- and moderate-shedding animals. The test is also highly specific for detecting MAP DNA and is able to discriminate between Mycobacterium avium var paratuberculosis and other fecal Mycobacteria species. 

Collect feces directly from the rectum if possible. Place at least 2 grams (1 tablespoon) into sterile plastic container. Use permanent marker to label vial with animal ID. Submit cooled samples to the ISU VDL as soon as possible. Do not freeze.

Pooled Fecal PCR Mycobacterium paratuberculosis

ISU VDL offers a pooled fecal PCR test for Johne’s Disease diagnosis in cattle. The test is run similarly to the direct fecal PCR, but will allow pooling of up to 5 fecal samples with results available in 3-5 days. This can reduce testing costs and increase choices in testing strategies. If a pool is positive, testing of individual samples with PCR or culture can be performed.

Sample collection from individual animals is the same as the direct fecal PCR. Collect feces directly from the rectum if possible. Place at least 2 grams (1 tablespoon) into sterile plastic container. Use permanent marker to label vial with animal ID. Submit cooled samples to the ISU VDL as soon as possible. Do not freeze or pool the samples. POOLING PROCEDURES WILL BE DONE AT THE VDL.

Guidelines for Fecal Collection and Submission

For animals tested under the IDALS State Johne's Program, use the Iowa Johne's Program submission form as provided by IDALS. 

For non-program submissions use the ISU VDL ruminant submission form. Please include animal number, age, and production class (i.e. stage of lactation). Test results are most accurate if samples are not frozen.  For submission of more than 10 samples, please call the ISU VDL to schedule a submission date.  Tests are run on Monday, Tuesday, and Wednesday, so samples arriving on these days will be processed on the same day.

Collect fecal samples directly from rectum (unless doing environmental sampling).  Do not collect ground or floor samples.  Use a separate, dry glove to collect individual sample (moisture and lube may adversely affect the pH of the sample). Place a minimum of 5-10 grams (1/2 ounce or 1 tablespoon) into sterile, plastic container (rectal sleeves and gloves will not work).  We recommend Fisher brand Polystyrene Sample Vials (catalog # 03-341-13) or similar containers for submissions. Use permanent ink to label container with animal ID and premise ID if available. Place container in cooler with cold packs so samples will cool quickly.  Transfer samples to refrigerator ASAP.  Do not freeze in commercial freezer.  Include ice packs to keep samples cool during shipping.  Samples must be processed within 96 hours of collection or frozen to -70ºC at the laboratory for later processing. For fecal pooling, five individual animals of similar ages/lactations will be combined in a pool.  POOLING PROCEDURES WILL BE DONE AT THE VDL. 

Submission forms should contain ID numbers and ages for all animals.

More Information

Powerpoint presentations available for download

The Iowa Department of Agriculture and Land Stewardship (IDALS) is participating in the National Johne's Disease Control Program, which provides guidelines for detecting infected animals and minimizing risks to herd mates through management practices.  The goal of Voluntary Johne's Disease Program is to certify Johne's negative herds according to the USDA definitions.  IDALS has funding to subsidize producers' lab fees and veterinary participation in risk assessment.   Participation in the program is completely voluntary and the confidentiality of test results will be maintained within the limits of Iowa law.  For more information, please contact Dr. Eiben, Iowa Johne's Disease Coordinator, (IDALS), at 515-281-0866 or your state district veterinarian.

Contact Information

Please feel free to contact Dr. Adam Krull at or 515-294-1950 with questions.