The normal range of progesterone levels in dogs varies depending on their physiological stage and individual differences.

Here are detailed explanations of the normal progesterone levels in dogs:

Basal Progesterone Levels: During the normal non-estrus period, dogs tend to have lower progesterone levels. However, due to individual and breed differences among dogs, the basal progesterone level can vary.

Progesterone Levels During Estrus: During the estrus phase of female dogs, progesterone levels rise significantly. According to research, ovulation typically occurs 48 to 60 hours after the detection of LH0 (luteinizing hormone peak). At the LH+2 and LH+3 time points, the average serum progesterone concentrations are 4.8±0.9 ng/ml and 7.2±1.3 ng/ml, respectively. These values indicate that during estrus, the progesterone levels in dogs increase significantly.

Progesterone Levels During Optimal Breeding Time: When female dogs reach their optimal breeding time, the progesterone levels may range from 10 to 30 ng/ml, or even exceed 60 ng/ml. This indicates that the female dog has a high fertility rate during this period.

It is important to note that progesterone levels in dogs are influenced by various factors, such as age, breed, health status, and individual differences. Therefore, when assessing progesterone levels in dogs, a comprehensive analysis should be conducted based on specific circumstances.

Additionally, abnormal progesterone levels in dogs can affect their fertility. For example, low progesterone levels may lead to the inability of female dogs to experience normal estrus or conceive, while high progesterone levels may result in pseudopregnancy. Therefore, if abnormal progesterone levels are detected in dogs, it is recommended to consult a veterinarian promptly for diagnosis and treatment.