Serology has long been the mainstay of leptospirosis diagnostics.

The Bacteriology Laboratory at the MSU VDL conducts over 80,000 serologic assays for leptospirosis annually and performs the Microscopic Agglutination Test (MAT) daily, Monday through Friday. Because the test is performed daily, results are usually reported the same day samples are received—samples received later in the day will be reported the following day.

Our canine leptospiral MAT (test code 95055) includes antibody titers against the following six leptospiral serovars: Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. Titers against serovar Autumnalis are available in our expanded panel (test code 95066) or as an add-on (test code 95054) by request.

An interpretation is included in each MAT report at no extra charge and additional consultation is also available.

As with other serology assays, vaccination complicates the interpretation of titers. Please provide a leptospiral vaccination history if it is available. This vaccination history is used in combination with the appropriate clinical history and test request on the submission form to ensure the appropriate tests are requested, and to provide context for the interpretation. For example, please indicate on the submission form if the dog is ill (test is for clinical purposes) or if the test is being requested as part of a vaccine screen (test code 95996) to determine whether the dog needs to be given a booster dose of lepto vaccine.

In a clinical case, performing a PCR assay can detect the leptospiral DNA. The PCR assay (test code 95053) is a quick test with a two to five day turnaround time for a diagnosis.

However, due to the transient bacteremic phase of the disease, leptospira will not be detected by PCR in blood after the first few days of infection. Urinary shedding of leptospires is a sequelae of the disease; however, the bacteria may not be present (detected by PCR) in the urine of infected dogs until about five to seven days after they become ill. Antibiotic treatment will also negatively affect the chances of finding leptospires in urine using any method.

Testing with one sample/assay for leptospirosis is not ideal and a combination of serology and organism detection is recommended.

To provide our companion animal (and zoo animal) clients a more complete diagnostic package, we have combined the traditional leptospira serology assay (MAT) with PCR. The MSU VDL’s new leptospirosis panel (test code 95068) includes PCR (blood or urine) and MAT at a discounted price.

Remember that antibiotics will negatively impact the detection of leptospires. Please collect urine and blood samples for PCR PRIOR TO beginning antibiotic treatment.

PCR:

• 1 mL of whole blood or 5-10mL of urine
• Ship samples on ice
• Samples should reach the lab within 24-48hr post collection; we recommend using the MSU VDL insulated mailer with UPS overnight return shipping

MAT:

• 0.5 mL of serum or plasma
• Refrigerate sample until shipment
• During hot months, we recommend shipping with an ice pack using the MSU VDL insulated mailer with UPS overnight return shipping
• Separated serum that has been stored ≤ 10° C may be tested up to 1 month post collection

MAT & PCR:

• 0.5 ml serum (or plasma) for MAT AND 5-10 mL urine (or 1 mL whole blood) for PCR
• Ship overnight with an ice pack; we recommend using the MSU VDL insulated mailer with UPS overnight return shipping

For more detail please see the MSU VDL catalog of available tests or call 517.353.1683.

To aid clinicians in discussions with dog owners, we also offer a client education guide, “Leptospirosis: What Every Dog Owner Should Know.” This guide can be printed or shared with clients electronically. Please contact us if you would like printed copies sent to your clinic.

We routinely test cattle for leptospirosis by serology and by PCR for urine and tissue samples. Serology is run daily, Monday through Friday. Urine samples are accepted Monday through Saturday and results are available within 2 to 5 days.

Serology testing includes antibody titers against the following 6 leptospiral serovars: Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A professional interpretation is provided for each sample. Please note that the antigen we use for serovar Hardjo will detect antibodies against both Hardjoprajitno and Hardjo-bovis.

Herd screening for leptospirosis is best accomplished by screening urine samples for organisms and then using serology to help indicate the infecting serovar of Leptospira. Please see Collection of Bovine Urine for Diagnosis of Leptospirosis for detailed instructions for the collection and submission of these samples.