contaminating bacteria that enter the uterus at parturition or during
attempts to manually remove the placenta.
Although reported by many authors as the treatment of choice, manual
removal of a placenta has many undesirable complications, including
severe hemorrhage. It is possible for the mare to lose large amounts of
blood into the uterus, and blood serves as an excellent environment for
bacterial growth. Pulmonary emboli have been reported following this
procedure, apparently because of dislodgment of naturally occurring
emboli from the uterine vein. Invagination or intussusception of the
uterine horn attached to the placenta can occur at the time of manual
removal. Another reproductive complication is a delay in uterine
involution. It has been suggested that manual removal of the placenta
can result in permanent endometrial damage. It is likely that manual
removal of the placenta is not the treatment of choice.
The old practice of tying weights (usually a 2 litre bottle filled with
water) to a retained placenta has been associated with invagination of
a uterine horn and even complete uterine prolapse. The author has
witnessed a uterine prolapse due to this technique, and is strongly
opposed to it. Although it has been recommended never to cut off the
membranes such that retraction of the placenta into the uterus would
occur, it is equally as bad to attach weights to the placenta to s peed
removal.
Flushing and siphoning of large volumes of fluid from the uterus is an
essential part of treatment of retained placentas. This technique dilutes
and evacuates bacteria and toxins from the inflamed uterus, and
induces stretch and reflex contraction of the myometrium.
The author’s favoured regimen is to begin treatment if the placenta has
been retained for over 6 hours. The mare is started on a course of
flunixin BID, Procaine penicillin BID and oxytocin IM bolus every 4
hours. The uterus is lavaged every 12-24 with large volumes of warm
water and a Neomycin / Polymixin antibiotic combination is instilled
after each flush. Very gentle manual traction is applied after each flush.
If there is resistance to traction, the placenta is left in place and the
uterus is flushed again in 12-24 hours. If the mare is pyrexic or
depressed, intravenous fluids are administered and systemic
gentamicin may be added to the treatment.
Retained foetal membranes may take up to 5 days to be expelled even
when treated appropriately, but usually the problem is resolved within
48 hours. When a retained placenta is finally passed and has been
shredded during its retention, it is difficult to state with certainty that all
of the membrane has passed. In the author’s opinion, if there is
uncertainty as to whether there is any placental tissue left, treatment
(including flushing) should be continued for an additional 24-48 hours.
15-‐18
February
2016
East
London
Convention
Centre,
East
London,
South
Africa
81