**2. Vulvitis, vaginitis, and cervicitis**

Vulvitis (inflammation of the vulva), vaginitis (inflammation of the vagina), and cervicitis (inflammation of the cervix) can develop due to different reasons such as difficult labor, chronic contamination of the reproductive tract due to poor conformation, sexually transmitted diseases, or mating. Bruises and hematomas (a pool of blood under the surface of the skin) of the vagina may be found in mares following delivery of a foal. Severe inflammation of the vulva and vagina, including local tissue death, may also occur [8]. Infectious vaginitis and cervicitis may occur as part of the uterine infection process or as a result of local irritation or laceration. Vaginal injuries secondary to breeding or parturition may lead to abscess formation and adhesions [9].

The sinus and fossa clitoral (the folded lining near the clitoris) should always be considered as a location of bacterial growth. The clitoral swabs are taken from the clitoral fossa and the clitoral sinuses to rule out acquired *Pseudomonas aeruginosa, Klebsiella pneumoniae,* and *Taylorella equigenitalis.* The signs of severe inflammation can include an arched back, elevated tail, poor appetite, straining, swelling of the vulva, and a foul smelling, watery discharge. Signs begin 1–4 days after birth and last for 2–4 weeks. In most cases, supportive care and treatment with antibiotics are sufficient [10].

Among causes that produce infectious vulvitis and vaginitis include contamination by *P. aeruginosa* and *K. pneumoniae* or venereal transmission produced by equine coital exanthema, contagious equine metritis (CEM), and dourine. Although the primary route of transmission is venereal, outbreaks have been documented in which transmission occurred through contaminated supplies and instruments or by the use of a single glove for rectal examination of many mares [11].

*P. aeruginosa* and *K. pneumoniae* cervicitis can be spread between horses by venereal transmis‐ sion. Bacteriological studies should be routinely performed on recently introduced mares and stallions to prevent such infections. Culture is also indicated if there is an increased incidence of endometritis on a stud farm. Pre- and post-ejaculation urethral swabs and semen obtained from stallions should be cultured. Routine washing of the stallion penis with antiseptic solution before and after breeding is contraindicated because it may disturb the normal bacterial flora of the penile surface and promote growth of these pathogenic bacteria [1, 12]. Mares infected with *P. aeruginosa* and *K. pneumoniae* discharge greenish-tinged pus with a sweet "grape-like" odor by endometritis.

Equine coital exanthema is a benign venereal disease caused by equine herpesvirus type-3 (EHV-3). EVH-3 is a member of the subfamily Alphaherpesvirinae [13]. Although the primary route of transmission is venereal, outbreaks have been documented in which transmission occurred through contaminated supplies and instruments or by the use of a single glove for rectal examination of many mares [14]. Clinical signs in mares might develop 4–8 days after sexual contact and are clearly expressed by the presence of numerous circular red nodules up to 2 mm in diameter on three different parts of the genital tract: vulvar and vaginal mucosa, the clitoral sinus, and perineal skin. These lesions primarily develop into vesicles, then into pustules and eventually rupture, leaving shallow, painful, ulcerated areas that may amalga‐ mate into larger lesions. Edema can develop in the perineum and may extend between the thighs. Sometimes, ulcers will be found on the teats, nasal mucosa, and lips. Secondary infection of the ulcers by *Streptococcus* spp. is common, causing ulcers which exude a muco‐ purulent discharge, and the mare may become febrile. Without these secondary bacterial infection occurs, skin healing is complete within 3 weeks, but clitoral and vaginal ulcers heal slowly. Skin lesions persist for long periods as unpigmented scars; however, pregnancy rates are not reduced. Lesions in stallions are similar to those described in mares and are found on both the penis and prepuce. Therefore, copulation may be difficult because intromission is painful, and the stallion usually refuses to mount and copulate. If copulation does occur during the ulcerative stage, ulcers can cause bloody ejaculates, reducing sperm viability [11]. Although coitus is the major route of exposure for stallions and mares, mares can be infected by AI or thorough indirect contact with contaminated veterinary instruments or equipment, gyneco‐ logical examination or testing for pregnancy [11, 14, 15].

Dourine also produces vulvitis, vaginitis, and cervicitis in the mare. Dourine is sexually transmitted disease caused by the protozoan parasite, *Trypanosoma equiperdum.* This pathology is spread during natural or artificial breeding, foaling, and in the milk of infected mares. Transmission from stallions to mares is more common, but mares can also transmit the disease to stallions. The incubation period is a few weeks to several years. *T. equiperdum* can be found in the vaginal secretions of infected mares and the seminal fluid, mucous exudate of the penis, and sheath of stallions. Affected animals include swelling of the vagina and vulva and mucopurulent vaginal discharge pus by their vulva (females) or urethra (males). Inflammation of vulva and vagina may extend along the perineum to the ventral abdomen and mammary gland. The genital region, perineum, and udder may become depigmented. Clinical signs of dourine can be nonspecific and include fever (temperature greater than 38.6°C), conjunctivitis, weight loss, skin plaques that may become depigmented, and neurologic signs [1, 16]. Dourine usually not causes endometritis, but abortion can occur with more virulent strains [17–19]. Approximately 50–70% of infected horses die [1, 16, 18, 20].

CEM is a transmissible, venereal disease of horses produced by the bacterium *T. equigenita‐ lis.* Compared with other breeds, Thoroughbred horses appear to be more severely affected by the disease. Due to the animals may be asymptomatic, the disease is difficult to detect and control. CEM is a serious disease because it is highly contagious and can have a devastating effect on equine reproductive efficiency. Transmission may also occur indirectly by AI or contact with contaminated hands, instruments used for practitioners or at breeding facilities following international horse shipments. Undetected carrier mares and stallions are the source of infection of the disease during the breeding season. Normally, a carrier stallion can infect several mares before the disease is diagnosed. The sites of persistence in mares that are clitoral carriers are the clitoral sinuses (medial and lateral) and the clitoral fossa [21], for an extended period of time [18]. Mares with CEM shows edema and hyperemia of the vaginal mucosa, cervix and endometrium [18], resulting in infertility, failures to conceive (revealed by an early return to estrus after breeding), or spontaneous abort [22].

Other microorganisms that have been isolated from fossa and sinus clitoral are *Escherichia coli*, *Streptococcus faecalis*, *Corynebacterium* spp., *Staphylococcus aureus*, β-hemolytic Streptococ‐ cus, *Bacillus*, *Enterobacter aerogenes*, Pasteurella spp., α-hemolytic Streptococcus, Citrobacter, and Proteus [23]. When suspected carrier status level of the clitoris, the clitoris is advisable to treat/lobby before examining the uterus to prevent the risk of transmission of infection to the cervix.
