Rupture of the mesocolon as a cause of recurrent colic in a showjumper mare

An 11‐year‐old Italian Saddlebred showjumper mare was referred for investigation of recurrent colic. The mare had undergone surgery for left dorsal displacement of the ascending colon 5 years previously and had subsequently experienced several episodes of colic that had responded to medical treatment. Due to deterioration of the mare's clinical condition in the last episode, characterised by unrelenting pain and worsening of the cardiovascular parameters, the mare underwent repeat surgery for suspected colonic displacement. Exploratory laparotomy revealed a complete rupture of the mesocolon of the ascending colon. The mesocolon was repaired and the mare recovered uneventfully. She returned to training and competition and only a single episode of mild transient colic was recorded in the follow‐up.     

Disruption of the blood supply to the small colon following rectal prolapse and small colon intussusception in a mare

A coliky and depressed four year old Arabian mare was examined three days after replacement of a rectal prolapse that had occurred during parturition. Fresh blood was present in the rectum and a septic peritonitis was diagnosed based upon the clinical pathological examination of the peritoneal fluid. At laparotomy the terminal 1.3 meters of small colon was found to be necrotic as a result of rupture of the terminal mesocolon and associated blood vessels. Based upon the poor prognosis the mare was euthanized. Rupture of the mesocolon was thought to be a sequel to the rectal prolapse. The anatomy predisposing the horse to these events is discussed.     

Permanent colostomy after small colon prolapse in a parturient mare

Small colon prolapse is a possible complication during parturition and diarrhoea. A case diagnosed in a mare during birth labour was reduced by the attending veterinarian at the farm, and referred to the authors for evaluation. After thorough physical examination, blood and peritoneal fluid tests, a ruptured mesocolon was suspected and the mare explored under general anaesthesia by a median celiotomy approach. During the procedure the affected mesocolon‐rectum was confirmed and a resection of the intestine elected. After prolapsing the segment of damaged viscera a permanent end colostomy was performed. Fourteen months later and after an uneventful recovery, the mare was in a very good physical condition and waiting to be covered for the next breeding season.     

Large colon strangulation due to a diaphragmatic hernia in a mare: A case report

This report describes a case of diaphragmatic hernia with incarcerated large colon in a 16-year-old Tennessee Walking Horse mare. This mare was presented with an acute episode of abdominal pain that was not responsive to analgesic therapy. Treatment consisted of resection of the devitalized large colon and closure of the rent in the diaphragm.     

Surgical correction of entrapment of the large colon and caecum through a mesoduodenal rent with standing laparoscopic repair in a mare

A 12-year-old Tennessee Walking Horse mare displaying signs of severe colic for 48 h was found during an exploratory celiotomy to have entrapment of a cranially displaced large colon and the caecum through a rent in the mesoduodenum. The entrapment was relieved, and 24 h later, the mesoduodenal rent was closed laparoscopically, with the mare standing. The owner reported 6 months later that the mare had displayed no signs of colic since being discharged from the hospital 11 days after surgery.     

Mesenteric tears of the descending (small) colon as a postpartum complication in two mares.

Segmental ischemic necrosis of the descending colon associated with discrete tears of the mesocolon were diagnosed in 2 mares following foaling. After foaling, both mares had a slow onset of signs of abdominal pain and gradual deterioration of clinical status. Increases in peritoneal fluid total protein concentration and WBC count and a palpable impaction of the descending colon on examination per rectum were useful diagnostic aids. Surgical intervention was successful in one mare, but not in the other.     

Thoracotomy for repair of a large dorsal diaphragmatic hernia in an 18‐year‐old mare

An 18‐year‐old Arabian‐mix mare was presented with a history of severe colic. Emergency exploratory celiotomy revealed diaphragmatic hernia, with a large rent in the left dorsal aspect of the diaphragm and large colon volvulus. Attempts to close the defect in the diaphragm in dorsal recumbency were unsuccessful. Therefore, a thoracic approach through lateral thoracotomy was elected, and a mesh was attached to the diaphragm using skin staples. While in dorsal recumbency, the mare suffered from significant respiratory acidosis. Thus, the mare was tilted into reverse Trendelenburg (30° head upward) and ventilation improved markedly. The mare recovered uneventfully, and was doing well 5 years after surgery.     

Eversion of the Urinary Bladder: A Sequel to Third-Degree Perineal Laceration in the Mare

Two cases of urinary bladder eversion are described in association with third-degree perineal lacerations in the mare. One case of eversion followed surgical repair of the perineal defect. The other occurred spontaneously in a 5-month postpartum mare awaiting repair of a third-degree perineal laceration. Both everted bladders contained the pelvic flexure of the large colon, and in 1 case a bladder rent allowed evisceration. Surgical intervention was required, and was successful in one case.     

Small-colon rupture attributable to granulosa cell tumor in a mare

A large granulosa cell tumor was believed to be responsible for causing obstruction and subsequent rupture of the small colon in a 10-year-old Quarter Horse mare. Two months earlier, a mass, tentatively diagnosed as granulosa cell tumor of the left ovary, had been identified by means of rectal palpation and ultrasonography. The mare was evaluated for clinical signs of acute, severe, abdominal pain, increased heart rate, cyanotic mucous membranes, clinical dehydration, with high PCV, leukopenia, and extreme abdominal distension. A large soft tissue mass and taut band that constricted the lumen of the small colon were palpable per rectum. Septic peritonitis was diagnosed on the basis of results of abdominocentesis. Exploratory surgery revealed extensive fecal contamination of the abdominal viscera, and the mare was euthanatized because of the resultant poor prognosis. At necropsy, the small colon was occluded by a taut, left broad ligament and the ovarian mass that was proved to be a granulosa cell tumor. The occlusion had caused impaction of the small colon, with subsequent perforation at the level of the broad ligament.     

Chronic intestinal pseudo-obstruction in a horse: a case of myenteric ganglionitis

An 11-year-old Quarter horse mare was presented for recurrent episodes of colic. A chronic intestinal pseudo-obstruction was diagnosed. Medical treatment and surgical resection of the colon were performed but the condition did not improve and the horse was euthanized. Histopathological examination revealed a myenteric ganglionitis of the small intestine and ascending colon.     

Laparoscopic repair of a small intestinal mesenteric rent in a broodmare

OBJECTIVES : To describe standing laparoscopic repair of mesoduodenal rent inaccessible by ventral median celiotomy. STUDY DESIGN : Clinical case report. SAMPLE POPULATION : A 6-year-old Thoroughbred broodmare with a right displacement of the dorsal colon and small intestinal incarceration in a mesoduodenal rent. METHODS : Two days after correction of a right dorsal displacement of the ascending colon, small intestinal incarceration, and partial closure of mesoduodenal rent, standing left and right flank laparoscopy was used to explore the abdomen to identify the mesoduodenal defect. The mesenteric rent was repaired from right flank portals by approximation with hemostatic clips. RESULTS : Approximation of the mesoduodenal rent was achieved with laparoscopic clips. No further complications or signs of abdominal pain occurred over the following year. CONCLUSIONS : Mesenteric rents in the mesoduodenum can be repaired by laparoscopic techniques in the standing horse. CLINICAL RELEVANCE : Use of laparoscopic techniques in the standing horse should be considered for mesoduodenal rents that are not accessible form a ventral median celiotomy.     

Volvulus of the colon in a horse associated with a mesocolic-umbilical band

A 7-years-old Clydesdale mare was presented with severe abdominal distension and acute colic. Dilated large intestine was palpated per rectum and a ventral midline exploratory laparotomy was performed. A 180 degrees volvulus of the pelvic flexure was present, associated with an inelastic band of tissue connecting the mesocolon to the umbilicus. The band was ligated and transected, and the volvulus reduced. Postoperative complications included hyponatraemia, metabolic acidosis and laminitis. The possible aetiology of the mesocolic-umbilical band is discussed.     

Colic in a Mare Caused by a Colonic Neurofibroma

A 16 year old Thoroughbred mare was presented to the Ontario Veterinary College because of an acute episode of colic. An exploratory laparotomy was performed and a neurofibroma was identified and successfully removed from the small colon. The clinical and pathological features of this case are discussed.     

Extensive resection and anastomosis of the descending (small) colon in a mare following strangulation by a mesenteric lipoma

A 17-year-old Quarter Horse, Arabian crossbred mare presented with a history of having had abdominal pain for 2 d. At surgery there was 2.6 m of descending colon strangulated within the pedicle of a mesenteric lipoma. The lipoma was resected and the descending colon appeared viable so was replaced, and the mare recovered from anaesthesia. Post-operatively, the mare failed to stabilise so was taken back to surgery. There was 2 m of infarcted descending colon which was resected and anastomosed. A drain and stainless steel stay sutures were incorporated into the ventral suture line. Post-operatively the ventral wound became infected but was resolved with therapy. The diagnosis, surgical and post-operative management and outcome are discussed.     

A standing pararectal approach to treat small colon obstruction by a pedunculated lipoma

In an 18-year-old Paso Fino mare presented with mild colic of 36 h duration, a luminal obstruction was found on rectal palpation in the most oral part of the rectum, and this appeared to be caused by a tight band on the left side. A standing procedure was used that involved pararectal dissection with long-handled instruments to the level of the constricting band, guided by a hand in the rectum. A hooked bistoury designed for treating entrapped epiglottis was used to transect the band, which immediately released the obstruction and allowed manual evacuation of the aboral end of the small colon. The band was most likely the pedicle of a pedunculated lipoma that had encircled the oral end of the rectum. The mare made a complete recovery.     

Laparoscopic repair of a ruptured bladder in an adult mare

A bladder rupture suffered by an adult mare during parturition was repaired, using a laparoscopic approach with the mare in dorsal recumbency. During the laparoscopic approach, the bladder was empty, inverted and had a rent on the dorsal apical surface. The bladder was located far caudally within the pelvis. By grasping the left lateral ligament and exerting gentle traction, it proved possible to manoeuvre the bladder more cranially where the rupture could be sutured. The benefits of the laparoscopic approach are reduction in incision size, visualisation of the tear, reachability of the empty bladder and the tear, and reduced reconvalescence time.     

Atrial fibrillation in a pregnant mare: treatment with quinidine sulfate

Atrial fibrillation in a pregnant, lactating, 15-year-old mare nursing a 70-day-old foal was converted to normal sinus rhythm, using quinidine sulfate. The maximum concentration of quinidine was 4.3 mg/L in the mare's milk and was 2.6 mg/L in the mare's serum. Treatment with quinidine did not interrupt the pregnancy. Six months after treatment, the mare developed acute volvulus of the large colon and died. At necropsy, the mare did not have macroscopic or microscopic cardiac lesions. The fetus was macroscopically and histologically normal.     

Marsupialization of an abdominal abscess caused by Serratia marcescens in a mare

An intra-abdominal abscess was diagnosed in a 7-year-old mare by palpation per rectum and from abnormal clinicopathologic findings. Initial treatment with procaine penicillin for 21 days was unsuccessful in halting the deterioration of the physical condition of the mare. Surgical exploration of the abdomen revealed a mass in the wall of the left ventral colon. Drainage was achieved by marsupialization. Serratia marcescens was isolated from the abscess. Recovery appeared complete, and the mare has resumed broodmare capability.     

T-shaped malformation of the ventral colon in a Thoroughbred filly with colic

A 4-month-old Thoroughbred filly presented for abdominal pain was diagnosed with a T-shaped malformation of the ventral colon at exploratory laparotomy. Following resection and anastomosis of the large colon, no further episodes of abdominal pain occurred during a 12-month follow-up. Acute dehiscence of the linea alba occurred as a complication of the initial laparotomy, but was successfully managed following additional surgical repair. T-shaped malformation of the ventral colon has not previously been reported and is considered a congenital malformation of mesocolon formation.