Infectious endometritis is one of the main causes of subfertility/infertility in the mare. In this report, we present the first case of endometritis in mare associated with a strain of Enterococcus casseliflavus, an unusual gram-positive bacterium which can also be a zoonotic agent. Furthermore, the isolated strain showed a worrying multidrug-resistant profile. The accurate finding of a successful antimicrobial treatment and consequently, the pregnancy diagnosis indicate the importance to isolate, identify and define the antibiotic resistance profile of bacteria associated with endometritis.

Infectious endometritis is one of the main causes of subfertility/infertility in the mare. In this report, we present the first case of endometritis in mare associated with a strain of Enterococcus casseliflavus, an unusual gram-positive bacterium which can also be a zoonotic agent. Furthermore, the isolated strain showed a worrying multidrug-resistant profile. The accurate finding of a successful antimicrobial treatment and consequently, the pregnancy diagnosis indicate the importance to isolate, identify and define the anti-biotic resistance profile of bacteria associated with endometritis.