Page 473 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

448 CHAPTER 2

VetBooks.ir 2.56 measures to minimise the risk of infection or to con-
trol an outbreak. Surgical correction of poor peri-
neal conformation may reduce the incidence of
placentitis in some mares.

Prognosis
If the placentitis is identified early and aggressive
treatment initiated, then up to 73% of cases may
result in a live foal. Unfortunately, the inflamma-
tion and infection is often in an advanced state when
identified and abortion is a common outcome.

FETAL MUMMIFICATION

Definition/overview
Fig. 2.56 Part of the placenta of a Thoroughbred This is an uncommon occurrence given the rou-
mare that had foaled following a late-pregnancy tine ultrasound monitoring of the early pregnancy.
vaginal discharge. There are areas of placental If intrauterine fetal death occurs and the cervix
thickening and brown discolouration due to a focal remains closed, the fetus is retained and may become
placentitis of bacterial origin. ‘mummified’. In the case of twins, the live fetus may
continue normally to term, when the mummified
fetus is delivered at the same time as the normal foal.
Management In single foal cases, which are rare, the mare may
Treatment is aimed at controlling the infection, spontaneously abort the dead fetus at any time or
reducing inflammation and encouraging uterine qui- enter an extended period of anoestrus.
escence. How advanced the placentitis is at the time
of diagnosis will dictate whether medical treatment Aetiology/pathophysiology
is likely to be successful. In all cases of placentitis, Bacterial or mycotic placentitis may cause fetal death
but particularly those with advanced changes, abor- and, where the mare is treated with antimicrobi-
tion is a potential outcome despite treatment. Broad- als and progesterone, this may result in the cervix
spectrum antibiotics that have good penetration of remaining closed and retention of the dead fetus.
the placental and fetal tissues (e.g. potentiated sul- If the fetal sac remains sterile, its fluid contents are
phonamides, penicillin/gentamycin combination), resorbed, the fetus dehydrates and it becomes mum-
anti-inflammatories (phenylbutazone, flunixin), pro- mified. The most common scenario is in cases of
gesterone supplementation and pentoxyifylline are twinning when one of the fetuses spontaneously dies
the routine medications used. Acetylsalicylic acid and subsequently mummifies, while the pregnancy is
(aspirin) has been used to improve uterine blood maintained by the remaining live fetus. The mum-
flow. Treatment is continued until parturition and mified fetus may macerate in utero over time or as a
repeated ultrasound assessment of the CTUP is per- result of an ascending infection via the cervix, lead-
formed to assess response to treatment. ing to a vulval discharge.
Where a live foal is delivered, any prematurity or
abnormal vaginal discharge in the mare around deliv- Clinical presentation
ery should immediately class the foal as ‘high risk’ of Spontaneous abortion of a mummified fetus can
being infected, and appropriate neonatal monitoring occur at any time in the pregnancy, but most com-
and therapy should be instigated to avoid septicaemia. monly in the second trimester (Fig. 2.57). There is
Strict stud hygiene, immediate isolation of prolonged anoestrus or variable cyclicity after a pos-
aborted mares and fetuses and the use of vaccination itive pregnancy diagnosis. The mummified fetus is
for EHV-1 and EVA, where available, are essential delivered at term as a single pregnancy or alongside