Page 489 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

464 CHAPTER 2

VetBooks.ir and the period from foaling to beginning of the foal POST-PARTUM COMPLICATIONS
heat, decrease in the summer months. Some mares
will not show behavioural oestrus during the foal
urgently if abdominal pain continues or worsens, if
heat due to the presence of the foal and the moth- Complications should be suspected and investigated
er’s protective instincts. A decision on whether to pulse or respiratory rate rises, if the mucous mem-
breed the mare on the foal heat should be made on branes become pale or injected or if the mare sweats
an individual basis. It depends on the degree of uter- and/or shows no interest in the foal or food.
ine involution as determined during a full reproduc-
tive examination, the history of the foaling and the POST-PARTUM PAIN
immediate period thereafter, the time of year (par-
ticularly in the Thoroughbred), the type of mating Pain related to uterine contractions in the immedi-
used (i.e. natural covering or AI [not frozen semen]), ate post-partum period is most common in primipa-
the age of the mare (lesser fertility in older mares on rous mares and tends to be intermittent. There is
foal-heat breeding) and the time since foaling before usually a moderate increase in heart rate, with some
breeding (a minimum of 10 days post partum is used sweating. This usually subsides within 1–2 hours.
by many clinicians). Some clinicians delay the first Administration of analgesics is indicated in the
covering until after the foal heat, but ‘short cycle’ worst cases. Rectal palpation of the uterus and the
the mare by injection of prostaglandin 6–7 days fol- rest of the abdomen should be carried out to help
lowing foal-heat ovulation. This induced oestrous differentiate other more serious causes of abdominal
period is associated with an increased fertility com- pain such as large colon torsion, which occurs most
pared with foal-heat breeding. commonly in recently post-partum mares.

CONDITIONS ASSOCIATED WITH FOALING

UTERINE ARTERY RUPTURE the damaged vessels initially accumulates in the
mesometrium (broad ligament), where it may form
Definition/overview a haematoma, which helps stop further bleeding.
This is a well-recognised but uncommon condition
that can occur in the late-pregnant mare, but more
usually in parturient or immediately post-parturient 2.72
mares. It is more common in older, multiparous
broodmares, with the ruptured arteries bleeding into
the mesometrium or peritoneal cavity. It can present
with mild to moderate abdominal pain or, in severe
cases, shock and death. Treatment is symptomatic.

Aetiology/pathophysiology
The aetiology of uterine artery rupture is unknown,
but rupture (typically 2–3 cm long and longitudinal)
can occur in any of the following arteries: middle
uterine, utero ovarian, and external iliac (Fig. 2.72).
It is more common in multiparous mares >12 years
old. Some clinicians believe this may contribute
to progressive weakening of the arteries and pre- Fig. 2.72 Post-mortem view of the ovary and broad
disposition to rupture. There may be a predilec- ligament of a mare that died because of a uterine artery
tion to right-sided rupture. Haemorrhage from rupture that bled from the ligament into the peritoneum.