For all three bacteria, infection can be transmitted between horses in any of the following ways:
• direct transmission during natural mating;
• direct transmission during teasing. An infected teaser can transmit disease to mares through contact with his genitalia;
• indirect transmission during teasing. A teaser can transmit infected vulval discharge between mares through genital or naso-genital contact;
• transmission to mares if semen used for AI comes from infected stallions or has been contaminated with the bacteria during semen collection or processing;
• indirect transmission via the hands and equipment of staff or veterinary surgeons who have handled the tail or genitalia of an infected horse.
Note: AI - see AI Guidelines
