Page 492 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Reproductive system: 2.1 The female reproductive tr act 467

VetBooks.ir ultrasonography is useful in late pregnancy cases to (10–20 IU q2 h). Mares with peritonitis will require
intensive treatment with intravenous fluid therapy
document the position and health of the fetus and
detect possible ruptures. Peritoneal fluid analysis
will reflect the depth and extent of the laceration and and prophylactic treatment for laminitis.
should confirm peritoneal haemorrhage and/or peri- Prognosis
tonitis. Laparoscopy can be used to confirm the tear The prognosis is guarded to grave depending on
and possibly to repair smaller ones. the extent and depth of the rupture, how soon the
tear is detected and treated, the degree of haemor-
Management rhage and contamination into the peritoneal cavity
Often these mares present late in the disease pro- and the complications of peritonitis, adhesions and
cess when secondary peritonitis has developed. secondary bowel damage. Partial-thickness tears do
Secondary intention healing of partial-thickness heal, but the mare should not be mated for at least
tears usually occurs as the uterus involutes and no 60 days, and then preferably by AI if possible. Mares
specific treatment is required other than oxytocin to with full-thickness tears should not be bred from
encourage uterine clearance and shrinkage. Uterine that breeding season.
lavage should not be carried out as this may exac-
erbate the problem. Occasionally, partial-thickness UTERINE PROLAPSE
tears, which only have the serosa left intact, pres-
ent and are treated similarly to full-thickness tears Definition/overview
with peritonitis. Tears presenting with peritonitis Uterine prolapse is an uncommon condition seen in
need to be treated by surgical repair with concurrent the parturient mare where there has been dystocia,
peritoneal lavage. This is usually achieved via a ven- obstetric manipulation or extraction, or excessive
tral midline laparotomy with postoperative lavage straining post partum. Complete uterine prolapse is
continuing for several days afterwards (Fig. 2.74). easily diagnosed and is a true life-threatening emer-
All mares diagnosed with a uterine rupture (par- gency, while prolapse or invagination of the tip of
tial or complete) require broad-spectrum systemic the uterine horn is often noted only at the first rou-
antibiotics, antiendotoxic NSAIDs and oxytocin tine post-partum examination. Treatment involves
replacement under sedation and epidural anaesthesia.

2.74
Aetiology/pathophysiology
Uterine prolapse can occur following dystocia, par-
ticularly if it is prolonged and/or excessively forceful
or quick extraction is carried out. It can also occur
following late-gestation abortion and secondary to
any condition leading to post-partum straining (e.g.
retained placenta, vulval/vaginal lacerations). The
uterus is often damaged to some degree and needs
to be carefully assessed for tears before replac-
ing. Uterine artery rupture can also lead to fatal
haemorrhage.

Clinical presentation
The recently foaled mare (several hours to, rarely,
Fig. 2.74 View at laparotomy showing a small tear days) presents with varying amounts of everted uterus
in the uterus of a recently parturient mare. Note at the vulval lips (Fig. 2.75). The uterus will appear
the inflamed serosa of the uterus subsequent to either bright or dark red, depending on the amount
generalised septic peritonitis. of haemorrhage present, with varying degrees of