Taylorella equigenitalis

Taylorella equigenitalis is a Gram-negative, non-motile, microaerophilic bacterium of the genus Taylorella, and the causative agent of contagious equine metritis (CEM) in horses. Phylogeny of T. equigenitalis includes being part of the Alcaligenaceae family.

Taylorella equigenitalis's distribution and habitat are primarily in the urethral fossa, distal urethra, prepuce, free-part of the penis of stallions and the clitoral fossa or sinus of mares. Canada and the USA are T. equigenitalis free, compared to other countries like those in Europe. Infected stallions are asymptomatic and act as the principal source of infection for mares during mating, and their carrier status may persist for many months or even years. A mare that becomes infected normally has recognizable signs unless asymptomatic, contributing to the spread of disease. A symptomatic mare can be identified by the mucus and pus being expelled from her vagina; CEM mares experience an inflamed endometrium causing low fertility and if pregnant a high probability for abortion in the first trimester.

Diagnosis, treatment and prevention of the disease are crucial to managing T. equigenitalis. Diagnosis is best done on chocolate agar or by polymerase chain reaction (PCR) with a sample from the urethral or clitoral fossa. Treatment includes disinfecting the external genital areas with 4% chlorhexidine as well as starting an antibiotic such as ampicillin. Prevention involves testing of new horses brought into the breeding herd, as well as isolation of horses entering T. equigenitalis free countries. Taylorella equigenitalis can have detrimental effects on the equine industry both clinically and economically due to the infertility it causes and the impact on import and export of equine genetics.