Page 512 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Reproductive system: 2.1 The female reproductive tr act 487

VetBooks.ir duct of debris, unfertilised oocytes, cellular deposits, Prognosis
Diseases of the oviduct are not easily diagnosed or
etc. Hysteroscopic-guided laser surgery of the utero-
tubal junction has been used in the treatment of
tions is always guarded.
abnormalities of this area. Exploratory laparotomy treated and therefore the prognosis for these condi-
allows the ducts to be lavaged and fimbrial adhesions
and cysts removed.

DISEASES OF THE VULVA, VAGINA AND CERVIX

PNEUMOVAGINA AND INCREASED leads to the dorsal vulva becoming more horizontal
CONTAMINATION OF THE CAUDAL and sloping, allowing air and fecal contamination
REPRODUCTIVE TRACT to occur. Finally, the vulva and its labia/constrictor
muscles can be damaged by repeated foalings, lead-
Definition/overview ing to stretching and lacerations, as well as repeated
Loss of normal perineal and vulval conformation vulval surgery. Damage may also occur to the peri-
through a multifactorial mix of conditions, such as neal body and vestibular sphincter with, or without,
trauma and the loss of perineal fat as a mare ages, vulval damage. This further compromises the func-
compromises the anatomical protective barriers tional barriers. Other factors include poor inherited
of the normal caudal reproductive tract. This allows conformation, ageing with loss of muscle tone in the
the creation of a pneumovagina, which increases the body generally and specifically in the caudal repro-
bacterial contamination of the vagina, cervix and ductive tract, pendulous abdominal conformation
uterus and leads to inflammation and infertility. and poor body condition. With the poor function
Careful assessment of the perineal and vulval con- of the caudal tract barriers, air and bacteria/debris
formation and structure can be carried out by visual can enter the tract, especially at oestrus, and create
and digital examination. The ascending infection a pneumovagina. The pneumovagina desiccates and
can be confirmed on a vaginoscopic examination inflames the mucosa, which, along with increased
with intrauterine bacterial swabbing and cytol- bacterial contamination, leads to a vaginitis/cervi-
ogy. Vulval and perineal body surgery is required citis that can ascend into the uterus and cause an
in many cases to resolve the problem permanently. endometritis.
Specific endometrial treatment is often not required
further after the vulval/perineal problem is resolved. Clinical presentation
The mare may be presented for a BSE, a routine
Aetiology/pathophysiology reproductive examination or following a history of
The vulva and vestibule act as the first barrier repeated unsuccessful attempts to breed. Abnormal
between the reproductive tract and the environ- vulval conformation, structure and/or tone may be
ment. The position of the ischium relative to the noted on visual and digital examination. The angle
vulva and the vulval dorsal angle will alter the com- and length of the vulva have been used to create a
petence of the vulvovestibular seal and predispose Caslick index (length of vulva in cm × angle of decli-
the mare to aspirating air and contamination into nation of vulva), which helps determine the necessity
the reproductive tract. Mares with good perineal and for a Caslick’s vulvoplasty operation. Values <150
vulval conformation have a vertical vulva with 80% and preferably <100 are associated with normal anat-
below the level of the pelvic floor. In some mares a omy and better fertility rates. The score increases
greater percentage of the labia appears to be situated naturally with age. The relative length or percentage
dorsal to the pelvic floor, which compromises vul- of the vulva above the ischium is also a major deter-
val function. A proportion of these mares develop a minant of the need for surgical treatment. The vul-
condition where the anus and rectum appear to be val lips should be parted manually above the ischium
pulled cranially towards the caudal abdomen, which and any aspiration of air into the vagina noted, as