The detection of progesterone levels during a dog's pregnancy is a crucial tool for assessing the maternal canine's pregnancy status

predicting the time of parturition, and monitoring fetal health. Below is a detailed analysis of progesterone index monitoring during canine pregnancy:

I. Purpose of Detection

• Assessing Pregnancy Status: Progesterone levels significantly increase during pregnancy, allowing for confirmation of successful conception through progesterone index monitoring.
• Predicting Parturition: Changes in progesterone levels are intimately linked to the timing of birth, enabling prediction of the dog's due date.
• Monitoring Fetal Health: Progesterone plays a vital role in maintaining pregnancy and fetal well-being, with its level fluctuations reflecting fetal development.

II. Timing of Detection

• Early Pregnancy: The first progesterone test is recommended within a certain period after mating (e.g., 10-14 days post-mating) to confirm pregnancy.
• Mid-Pregnancy: As pregnancy progresses, progesterone levels continue to rise. A second test during mid-pregnancy (e.g., 30-40 days post-mating) can monitor fetal development.
• Late Pregnancy: Nearing parturition (around 60 days post-mating), progesterone levels peak and remain stable. Monitoring at this stage can predict the birth date.

III. Methods of Detection

• Blood Sample Collection: Blood samples are collected from the pregnant dog for testing. The sample size is typically small, such as 75μL of serum/plasma.
• Detection Tools: Specialized progesterone test strips or immunofluorescence analyzers can be used for rapid, quantitative, and precise measurements.
• Frequency of Testing: The frequency depends on individual cases. Generally, tests can be conducted every two weeks during early and mid-pregnancy, and weekly or as needed during late pregnancy.

IV. Progesterone Index Trends

• Early Pregnancy: Progesterone levels gradually increase, though initial changes may be subtle.
• Mid-Pregnancy: Levels continue to rise and remain high, supporting the stability of the pregnancy.
• Late Pregnancy: Progesterone peaks and plateaus until shortly before parturition, when levels drop rapidly post-birth.

V. Precautions

• Sample Collection: Ensure adherence to aseptic techniques during blood sampling to prevent contamination.
• Detection Equipment: Utilize reliable and accurate equipment for progesterone detection to ensure result accuracy.
• Professional Interpretation: Progesterone results should be interpreted by a veterinary professional for accurate assessments of pregnancy status and fetal health.
• Individual Differences: Recognize that progesterone levels may vary among different dog breeds during pregnancy, necessitating case-specific evaluations.

In conclusion, progesterone index monitoring during canine pregnancy is essential for assessing maternal pregnancy status, predicting parturition, and monitoring fetal health. By adhering to proper testing timings, methods, and precautions, accuracy and reliability of the results can be ensured.