Spontaneous recovery in dairy cows with subclinical endometritis

The aim of this study was to evaluate the dependence between the time of diagnosis and spontaneous recovery from subclinical endometritis (SE) in dairy cows. Postpartum gynecological control was performed on 512 multiparous Holstein cows, housed in three farms located in the south of the province of Santa Fe (Argentina), from April to October 2022. Experimental cows were those that were diagnosed as healthy, but after endometrial cytology, were positive to SE (n=56). Two gynecological control was performed to every cow with SE. Considering the moment in which the first control was made, cows with SE were separated into two groups: group M1: between 15 and 30 postpartum days (ppd) and group M2: between 31 and 60 ppd. Each group was reviewed after 15 days from the first control. After the second revision, three experimental groups were formed: AC group: cows that recovered spontaneously, ES group: cows that maintained the disease, and EC group: cows that developed clinical endometritis. A 49% of cows were diagnosed as healthy cows. After performing endometrial cytology, 78% of cows were healthy, and the remaining 22% of cows were positive for SE. There was a higher percentage of cows checked during M1 than during M2, and M1 had more than 60% of spontaneous recovery to SE, although these data did not differ between the studied moments (M1 and M2, P>0.05). Cows from the AC group presented an abrupt decrease in the % PMN-N found between the first and second endometrial cytology performed (12.1 ± 1.7 and 1.0 ± 0.2 % PMN, respectively; P>0. 0001). In conclusion, our results showed no dependency between the moment of diagnosis and spontaneous recovery of subclinical endometritis in Holstein dairy cows.