Retained Placenta as a Potential Source of Mastitis Pathogens in Dairy Cows

Abstract

(1) Background: Retained placenta (RP) and mastitis are relevant diseases in dairy cows. This study mainly aimed to evaluate the contamination of uterine fluid by mastitis pathogens in dairy cows presenting RP. (2) Methods: Uterine fluids were sampled at RP diagnosis (89 ± 15 h after calving) from 5 primiparous and 10 (parity: 2–5) multiparous cows. The real-time PCR methodology was used to identify 15 mastitis and uterine pathogens. Results were analyzed using multivariate logistic regression, including the factors fever and parity. (3) Results: The prevalence of Escherichia coli was 93.3% (95% CI: 70.2–98.9%); Staphylococcus spp. (93.3%; 95% CI: 70.2–98.9%), yeasts (92.9%; 95% CI: 68.5–98.7%), Trueperella pyogenes/Peptoniphilus indolicus (80.0%; 95% CI: 54.8–93.0%), Streptococcus uberis (78.6%; 95% CI: 52.4–92.4%) and Streptococcus dysgalactiae (57.1%; 95% CI: 32.6–78.6%) comprised the largest proportions of pathogens in uterine contamination. Strep. uberis was related to the presence of fever (relative risk: 1.6; 95% CI: 1.0–2.8; p = 0.05). (4) Conclusions: Dairy cows with RP can be a relevant source of mastitis pathogens in farms. Only Strep. uberis was linked to clinical signs of infection. A high proportion of yeasts was observed in uterine fluids. Further research is needed to evaluate the real impact of RP on mastitis prevalence in dairy herds.