The VMDL now offers serum progesterone testing via chemiluminescence assay. Currently the assay is performed on Tuesdays and Fridays; if demand is sufficient a more frequent testing schedule will be instituted. Cost per sample is $13. Serum is the appropriate sample. For reliable results, collect blood into clot tubes without any clot facilitator or serum separator agent. Separate the serum from the clot within 2 hours of collection. DO NOT REFRIGERATE THE SPECIMEN PRIOR TO CENTRIFUGATION. Following separation, serum should be kept cooled or frozen and shipped to arrive at the lab as soon as possible. Do not collect and ship samples to arrive on the weekend.
The most common indication for measuring serum progesterone concentrations in dogs is to identify the optimal breeding time. On the day of the LH surge, the serum concentration of progesterone rises beyond 2 ng/mL in most bitches. Concentrations higher than 5 ng/ml indicate ovulation has occurred. Bitches are most fertile when bred 4-7 days after the LH surge.
In alpacas and llamas progesterone testing is used to diagnose pregnancy. Females that do not return to estrus for three weeks after breeding are tested. Concentrations higher than 2 ng/mL indicate pregnancy with greater than 90% certainty, whereas concentrations below 2 ng/mL indicate that the female is not pregnant.
There are other less common indications for the measurement of serum progesterone concentrations. Dr. Dietrich Volkmann or Dr. Dawna Voelkl, both of the Theriogenology Section of the Veterinary Medical Teaching Hospital can be contacted to help with the interpretation of results (call 573 – 882 6857). For service and billing related questions please call the VMDL.