Page 516 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Reproductive system: 2.1 The female reproductive tr act 491

VetBooks.ir PERSISTENT HYMEN through the new hole and breaking the fold down
manually. Subsequently, the accumulated uterine
Definition/overview
Maiden mares often have a remnant of the hymen fluid drains away.
present, which varies in size and completeness. Very Prognosis
occasionally it forms a complete membrane, which The prognosis is good for future fertility as long as
can bulge between the lips of the vulva. no congenital defects of the tract are present.

Aetiology/pathophysiology VARICOSE VEINS OF THE VAGINA
Some remnant of the hymen is normal in maiden
mares and is found just cranial to the urethral orifice Definition/overview
at the junction between the vestibule and vagina. It Prominent and varicosed veins are a common occur-
can consist of a loose fold of thin tissue forming a low rence in the dorsal vaginal wall, at the level of the
ridge of less than 2 cm height ventrally on the floor remnants of the hymen, just cranial to the urethral
of the caudal vagina. More unusually, there can be orifice. They are more common in older mares,
strands of tissue more dorsally crossing the vagina, especially in late pregnancy, and can cause intermit-
or a complete membrane. The latter condition stops tent vaginal bleeding.
the flow of endometrial gland products down the
reproductive tract, and these accumulate behind the Aetiology/pathophysiology
membrane causing it to bulge out between the vulval The cause of the varicosity of the veins is unknown,
lips. but they increase in incidence with age and multi-
parity, may be responsive to hormonal changes and,
Clinical presentation once present, persist. They rarely haemorrhage all
Persistent hymen may present as minor haemor- the time and usually bleeding is associated with
rhage from the vulval lips after the first covering of partial rupture of the vessels in late pregnancy or,
maiden mares. The condition may prevent the pas- occasionally, oestrus. The haemorrhage, which is
sage of a vaginal speculum and/or hand at the first usually slight, invariably stops spontaneously after
reproductive examination of the maiden mare. Cases parturition.
where there is considerable buildup of fluid behind
the complete hymen occur in post-puberty mares Clinical presentation
that are cycling and these may present with a bulg- Varicose veins may be detected as an incidental find-
ing, rounded, bluish-white tissue between the vulval ing at a reproductive examination. They usually
lips, often noted when the mare is moving at grass. present as intermittent, slight, fresh haemorrhage
from the vulval lips in older, late-pregnant mares
Diagnosis or, less commonly, during oestrus, particularly after
Diagnosis is by vaginal examination via speculum or breeding. Once the veins are established the bleed-
manually. Rectal palpation and ultrasonography of ing may occur every year in late pregnancy or, in
the entire reproductive tract will confirm that there severe cases, at every mating. An increase in inci-
is a tract cranial to the membrane and that this is not dence and/or severity should be investigated further.
a severe congenital deformity. There may be fluid
accumulated cranial to the hymen in the vagina and, Differential diagnosis
occasionally, in the uterus. Placental abnormalities; trauma to the reproductive
tract, especially post breeding or examination; uri-
Management nary tract haemorrhage.
Simple manual vaginal palpation will break down
fine strands or folds. In more complete folds it may Diagnosis
be necessary to sedate the mare and cut the centre Vaginal speculum examination will detect the
with scissors before placing the clinician’s fingers enlarged (1–3 mm), thin-walled, bluish veins, usually