severely (along with other signs of colic and endotoxemia) before, or
immediately after, foaling are often suffering from a rupture of the
caecum. In the immediate postpartum period, mares which tremble,
vocalize, have tachycardia and mucous membrane pallor are frequently
diagnosed with a uterine artery rupture.
Caecal rupture
Caecal rupture is the most common gastrointestinal catastrophe
associated with parturition. Ruptures immediately prior to parturition are
also seen. Rupture of a viscus incites a severe peritonitis. A rupture at
the tip of the caecum is the most likely site of rupture in the alimentary
tract. Affected mares typically present within 24 hours of parturition with
signs of abdominal pain which quickly progress to depression and
septic shock. In the author’s experience, this category of mare shows
mild colic signs, marked trembling, decreased responsiveness to
stimuli, and disinclination to move. These mares succumb to septic
shock, and the condition is likely to be rapidly fatal.
Rupture into the mesentery of the caecal base may temporarily limit
faecal contamination of the peritoneal cavity, with these differences
reflected in the peritoneal fluid analysis. Initially an abdominocentesis
may be normal, however later it reveals dark green-brown
gastrointestinal fluid that contains plant material and massively
increased neutrophil numbers. Humane euthanasia is indicated. There
have been no reports of successful treatment of this condition.
In preparturient caecal rupture, an immediate terminal caesarian
section is indicated. The author anaesthetizes such mares as
described above, delivers the foal by C-section and then euthanizes
the mare. Provided the diagnosis is made timeously, these foals
usually survive with minimal complications.
Uterine artery rupture
The hemorrhagic event can occur prior to parturition or during or postfoaling. The clinical presentations can be subtle or profound, with
hemorrhagic peracute blood loss into the abdomen, broad ligament, or
uterus. The clinical presentation may initiate as hemorrhagic shock,
abdominal pain, and weakness with compartmental syndrome, i.e.
broad ligament containment, or intramural (into the uterine wall). With
severe haemorrhage, cold ears and distal limbs, and elevated heart
rates over 80 bpm ae common. Some mares will be weak and appear
ataxic. A shrill whinny may be noted.Hemorrhagic discharge from the
uterus may be dramatic in a few cases.
The anatomical site of blood loss determines the prognosis for survival
by virtue of the opportunity for back pressure and tamponade, such as
is provided within the broad ligament. If the uterine artery rupture
occurs proximal to the ovary, hemorrhage occurs into the abdominal
15-‐18
February
2016
East
London
Convention
Centre,
East
London,
South
Africa
72