The relationship between cycle stage and results of uterine culture in the mare.

This research study explores the relationship between a mare’s cycle stage and the results of uterine culture. The study found no significant difference in the results of uterine cultures taken in different stages of the mare’s cycle, but suggests oestrus may be the preferred time for uterine examination.

Study Design and Methodology

The research involved taking swabs from the uterus of mares during two different phases of their reproductive cycle:

• The ‘in heat’ phase or oestrus (n=202).
• The ‘not in heat’ phase, either during seasonal anoestrus (no ovulation) or dioestrus (the period between two heat phases) (n=166).

Additionally, for deeper understanding, paired swabs were taken from some mares during both phases of their cycle.

Bacteriological Cultures

The swabs collected from mares were subject to bacteriological cultures for analysis. These were done aerobically (in the presence of oxygen) and the results were categorized as negative, insignificant or significant.

Culture Results and Analysis

The study identified a slight trend towards more positive cytological specimens during oestrus than during anoestrus/dioestrus. In numbers:

• Significant cultures were obtained from 12 out of 202 mares during oestrus (5.9%).
• Significant cultures were obtained from 14 out of 166 mares during anoestrus/dioestrus (8.4%).

Also, more mares had insignificant rather than negative cultures during oestrus as compared to anoestrus/dioestrus.

Association with Positive Cytological Specimens

Of the cultures classified as ‘significant,’ seven were associated with positive cytological specimens. Notably, just two specimens out of sixteen in which pure cultures of the bacterium E. coli were found also contained neutrophils, white blood cells indicative of inflammation or infection.

Findings and Recommendations

Despite the observed trends, the study ultimately found no substantial difference between the uterine culture results obtained during different stages of the mare’s cycle. However, due to the relative abundance of significant and positive cultures, the researchers suggested oestrus might be a more fruitful period for uterine examination.