Small Animal Surgical Emergencies. Группа авторов

be extrapolated from case reports and retrospective studies [13–21]. The condition is found primarily in dogs, although a few case reports affecting cats have been published [4, 13, 17]. In dogs, the condition is more commonly found in large breeds, with a higher incidence reported in German Shepherds [12] and English Pointers [9] and rare reports in small breeds [14, 16].

The history associated with presentation is typically considered to be acute to peracute and is often non‐specific (Figure 9.3). Clinical signs include weakness, restlessness, lethargy, recumbency, hematachezia, emesis, hematemesis, diarrhea, abdominal pain, abdominal distension, and/or shock [3, 9, 15].

      In most patients, physical examination reveals some degree of hypovolemic, septic, or toxic shock, depending on the duration of clinical signs [15]. Pale mucous membranes, tachycardia, prolonged capillary refill times, and weak peripheral pulses are common findings [12]. Abdominal pain and distension are typical, although not pathognomonic [18, 20].

Differential diagnoses that may present in a manner similar to intestinal volvulus include gastric dilatation and volvulus, intussusception, hemorrhagic gastroenteritis, viral gastroenteritis, intestinal foreign body obstruction, and trauma. While cause and effect is impossible to establish definitively owing to the paucity of reports in the literature, cases of intestinal volvulus have been reported to occur concurrent with other gastrointestinal diseases such as foreign body ingestion, parvovirus, gastric dilatation and volvulus, pancreatic insufficiency, lymphocytic–plasmacytic enteritis, ileocolic neoplasia, previous abdominal surgeries, congenital malformations, and trauma [6, 9, 10, 12, 16, 22]. While a relationship among these conditions is only speculative, identification of intestinal volvulus should prompt thorough evaluation for an underlying cause. One study demonstrates an association between intestinal volvulus and prior prophylactic gastropexy in a population of military working dogs [23]. Although rare, recurrence of intestinal volvulus is possible (Case Report 9.1).

Figure 9.1 Diagram of the visceral branches of the aorta with their principal anastomoses, ventral aspect.

      Source: H Evans and A de Lahunta (eds.) [2]. Reproduced with permission from Elsevier.

Figure 9.2 Intraoperative photograph illustrating the classic appearance of intestinal volvulus. Note the obvious diffuse necrosis and distension of the bowel.

Diagnostics

      Clinical pathological findings in patients with intestinal volvulus tend to be non‐specific. Normal to low packed cell volumes and plasma total solids are typical. White blood cell counts are normal to elevated. Serum chemistries are often normal or have non‐specific changes associated with gastrointestinal disease [6, 9, 18]. Given the similarities in the pathophysiology of the disease process with other conditions causing vascular compromise (such as gastric dilatation and volvulus), hypokalemia with metabolic acidosis and elevated serum lactate level would be anticipated. The only reported blood gas in a case of intestinal volvulus [10] revealed a metabolic alkalosis in a pattern similar to that seen with gastrointestinal foreign bodies [10,24–26]. Coagulation profiles have not been reported in the literature associated with this disease.

Figure 9.3 Decision‐making algorithm for a patient with an acute abdomen.

Case Report 9.1

A three‐year‐old male, neutered Great Dane was evaluated for a 24‐hour history of vomiting, diarrhea, inappetence, and lethargy. A physical examination was unremarkable. The owners elected symptomatic therapy and monitoring, including fasting and subcutaneous fluids, with a plan for recheck if vomiting and diarrhea persisted. Less than 12 hours later, lethargy and inappetence persisted, and the dog was reevaluated. At repeat presentation, the dog appeared dehydrated and painful during abdominal palpation. A tubular structure was palpated in the dorsal mid‐abdomen. Mucoid stool was noted on rectal examination. Abdominal radiographs were taken, and a small bowel obstructive pattern was seen with severe intestinal distension noted (Case Figure 9.1a). Abdominal exploration was recommended. Preoperative bloodwork revealed a mild metabolic acidosis. The remaining complete blood count and serum chemistry were unremarkable. At the time of surgery, the small bowel appeared cyanotic and an intestinal volvulus was identified and corrected. At the time of correction, the bowel appeared normal and viable. A prophylactic gastropexy was performed and the dog was recovered from anesthesia. The dog made an uneventful recovery other than a mild incisional infection that resolved with antibiotic therapy. Three years later, the dog was presented for evaluation of vomiting, diarrhea, inappetence, and lethargy of 12 hours' duration. On physical examination, the dog appeared dehydrated and was tachycardic. Gas distended loops of bowel and a possible mass in the left lateral mid‐abdomen were palpated. The abdomen did not seem painful. Abdominal radiographs were taken (Case Figure 9.1b,c), and marked gas and fluid distension of the bowel was noted. Intestinal volvulus was suspected. Given the prognosis associated with the disease and the dog's history prompting suspicion for recurrence, the owner requested humane euthanasia. Necropsy was declined.

Case Figure 9.1 Lateral abdominal radiograph of a Great Dane with severe, generalized distension of the intestines. Abdominal exploratory surgery was performed and an intestinal volvulus was identified and corrected (a). Three years later, the dog presented because of vomiting, diarrhea, inappetence, and lethargy of 12 hours duration. Two abdominal images were taken because of the large size of the dog (b and c). Marked gas and fluid distension of the bowel was noted. A recurrence of intestinal volvulus was suspected.

Abdominal radiographs are the most practically useful non‐invasive diagnostic tool aiding the diagnosis of intestinal volvulus. Patients typically have severe, prominent gaseous small bowel distension and may have loss of serosal detail (see Case Figure 9.1a). The distended bowel loops may lie parallel to each other and resemble a paralytic ileus [3, 6, 18, 20]. The stomach as well as the descending colon are often not dilated. Abdominal ultrasonography in humans has revealed a characteristic barberpole or whirlpool sign with mesenteric torsion, as the bowel loops encircle the mesenteric vasculature. [27, 28]. Similarly, computed tomography in humans demonstrates a characteristic “whirl sign”, which has also been reported in dogs [22, 29]. Definitive diagnosis is achieved at the time of abdominal exploration or necropsy.

Treatment

      Preoperative Treatment

Initial