Page 1381 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

1356 CHAPTER 14

VetBooks.ir 14.23 14.24

Fig. 14.23 A foal with uroperitoneum showing Fig. 14.24 Marked abdominal distension in a young
persistent posturing in order to urinate. foal with uroperitoneum.

Other signs include lethargy, weakness, progressive or GI compromise). The peritoneal fluid creatinine
abdominal distension (Fig. 14.24), mild colic and concentration will be at least twice that measured
going off suck. There may be a palpable fluid thrill in peripheral blood. If laboratory facilities are not
of the abdomen. Some preputial or perineal oedema available, methylene blue in sterile solution can be
may develop. This has been particularly noted with infused into the bladder via a urethral catheter; if
urethral or urachal rupture. Urine occasionally there is a defect in the bladder, it is subsequently
accumulates in the scrotum, and some foals have a found in the peritoneal fluid. Retrograde contrast
protruding perineum. Pyrexia is not usually present cystography and pyelography have been used in the
in classic cases of a ruptured bladder, but it will be past, but their major use now is in the diagnosis of
noted if infection is involved. Heart and respiratory ureteral and urethral defects. It should be noted that
rates are often increased with, in the later stages, obtaining urine during bladder catheterisation does
poor pulse quality, electrolyte-related dysrhythmias not rule out uroperitoneum.
and hypovolaemia. With severe electrolyte disorders Foals with uroperitoneum are typically hyper-
there may be CNS signs, circulatory collapse and kalaemic, hyponatraemic, hypochloraemic, hypo-
death. glycaemic, acidaemic and azotaemic owing to the
accumulation of urine in the peritoneal cavity and the
Differential diagnosis equilibration of electrolytes and fluid across the semi-
Meconium retention; other causes of colic. permeable peritoneal membrane. Foals that have
been receiving intravenous fluid therapy at the time
Diagnosis of diagnosis may not have classic electrolyte imbal-
History and a careful physical examination, includ- ances. Diagnostic tests to detect concomitant sepsis
ing abdominal palpation, are important. Diagnosis or bacterial peritonitis should also be performed.
is confirmed by ultrasound examination of the
abdomen (see Figs. 7.37–7.44). Large quantities of Management
free non-echogenic fluid are observed, and the blad- Uroperitoneum is initially a medical rather than sur-
der is often small, irregularly shaped and partially gical emergency. It is extremely important to achieve
or completely collapsed. The defect in the bladder metabolic stabilisation of foals prior to surgery, as
wall may be visible. The umbilicus should also be they present a high anaesthetic risk due to elec-
examined by ultrasonography. Ultrasound-guided trolyte abnormalities (particularly hyperkalaemia,
abdominocentesis can be used to collect perito- which can induce fatal bradyarrhythmias). Urine
neal fluid (urine), the analysis of which reveals a should be drained from the abdomen gradually,
low cell count and low specific gravity in uncom- while providing intravenous fluids to support the
plicated cases (those without concurrent peritonitis circulation and prevent acute hypotension following