History
A 1-year-old 32.0-kg (70.4-lb) sexually intact male black leopard (Panthera pardus) was referred for evaluation because of a long-term history of vomiting, ill thrift, and lethargy. The leopard and one of its siblings were acquired at 4 months of age, and since then, this leopard had vomited several times per week; however, approximately 1.5 months before referral, the frequency of vomition increased to 1 to 2 episodes/d. The owners reported that this leopard had always been substantially smaller and more lethargic than its sibling, which had no abnormal clinical signs. The leopard's diet consisted of beef, quartered chicken legs and thighs, and ground turkey meat. As the frequency of vomition increased, feeding was altered to provide smaller meals 2 to 4 times daily, with limited response. About 1 month before referral, results were negative for a fecal float assessment, and the leopard was treated with fenbendazole and famotidine (dosages not reported) for 5 days but did not have clinical improvement.
On referral examination, the leopard was thin (body condition score of 3/9); appeared quiet, alert, and fearful; and had a respiratory rate of 24 breaths/min (reference range, 16 to 40 breaths/min). For further physical examination and for point-of-care bloodwork, the leopard was premedicated with alfaxalone (1.70 mg/kg [0.75 mg/lb], IM) and ketamine hydrochloride (3.3 mg/kg [1.5 mg/lb], IM), and anesthesia was induced with alfaxalone (1.70 mg/kg, IV) and maintained with isoflurane (vaporizer setting, 1% to 2%) in oxygen (2 L/min). Results of bloodwork were unremarkable.1,2 On abdominal palpation, the stomach was considered thickened; however, no additional clinical abnormalities were detected. Thoracic and abdominal radiography was performed (Figure 1).
Left lateral thoracic (A) and cranial abdominal (B) and ventrodorsal thoracic (C) radiographic images of a 1-year-old 32.0-kg (70.4-lb) sexually intact male black leopard (Panthera pardus) evaluated because of a long-term history of vomiting, ill thrift, and lethargy.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Left lateral thoracic (A) and cranial abdominal (B) and ventrodorsal thoracic (C) radiographic images of a 1-year-old 32.0-kg (70.4-lb) sexually intact male black leopard (Panthera pardus) evaluated because of a long-term history of vomiting, ill thrift, and lethargy.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Left lateral thoracic (A) and cranial abdominal (B) and ventrodorsal thoracic (C) radiographic images of a 1-year-old 32.0-kg (70.4-lb) sexually intact male black leopard (Panthera pardus) evaluated because of a long-term history of vomiting, ill thrift, and lethargy.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Formulate differential diagnoses and treatment strategies from the history, clinical findings, and Figure 1—then turn the page →
Diagnostic Imaging Findings and Interpretation
Radiography revealed that the leopard's stomach was cranially displaced into the left caudodorsal aspect of the thorax and that the esophagus was severely and diffusely distended with a large amount of gas (Figure 2). Thin pleural fissure lines were present, and the trachea was shifted rightward and ventrally. The liver appeared enlarged, had rounded margins, and was ventrally displaced. On the basis of radiographic findings, the primary differential diagnoses included hiatal hernia, diaphragmatic eventration, and gastroesophageal intussusception. Given the prolonged duration of clinical signs, gastroesophageal intussusception was considered less likely; however, acute gastroesophageal intussusception or chronic sliding gastroesophageal intussusception was considered possible.3,4 Pleural fissures likely represented a small amount of pleural fluid.
Same radiographic images as in Figure 1. The esophagus (black arrows; A and C) is diffusely distended with a large amount of gas, and a large, round soft tissue opacity structure (white arrows; A through C) is in the left caudodorsal aspect of the thorax, consistent with hiatal hernia, diaphragmatic eventration, or gastroesophageal intussusception. The leopard is intubated with an endotracheal tube (asterisk; A) that extends to the thoracic inlet. The trachea (dotted line; C) is shifted rightward. Thin pleural fissure lines (arrowheads; A and B) are present, and the liver is mildly enlarged, has rounded edges, and is ventrally displaced (B). L = Liver.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Same radiographic images as in Figure 1. The esophagus (black arrows; A and C) is diffusely distended with a large amount of gas, and a large, round soft tissue opacity structure (white arrows; A through C) is in the left caudodorsal aspect of the thorax, consistent with hiatal hernia, diaphragmatic eventration, or gastroesophageal intussusception. The leopard is intubated with an endotracheal tube (asterisk; A) that extends to the thoracic inlet. The trachea (dotted line; C) is shifted rightward. Thin pleural fissure lines (arrowheads; A and B) are present, and the liver is mildly enlarged, has rounded edges, and is ventrally displaced (B). L = Liver.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Same radiographic images as in Figure 1. The esophagus (black arrows; A and C) is diffusely distended with a large amount of gas, and a large, round soft tissue opacity structure (white arrows; A through C) is in the left caudodorsal aspect of the thorax, consistent with hiatal hernia, diaphragmatic eventration, or gastroesophageal intussusception. The leopard is intubated with an endotracheal tube (asterisk; A) that extends to the thoracic inlet. The trachea (dotted line; C) is shifted rightward. Thin pleural fissure lines (arrowheads; A and B) are present, and the liver is mildly enlarged, has rounded edges, and is ventrally displaced (B). L = Liver.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
To further characterize findings, CT was performed and revealed that the left dorsal aspect of the diaphragm bulged cranially into the thorax, allowing cranial displacement of the entire stomach, proximal aspect of the descending duodenum, and associated mesentery (Figure 3). Disruption of the diaphragmatic margin was not identified, and a well-defined margin with smooth contour appeared maintained between the abdominal and thoracic cavities. The thoracic portion of the esophagus was severely, diffusely enlarged and distended, containing gas and fluid. Gastroesophageal intussusception was not evident. The right middle lung lobe had increased attenuation that effaced the pulmonary blood vessels and created air bronchograms and a lobar sign, consistent with pulmonary consolidation. On the basis of CT findings, the primary differential diagnosis was severe diaphragmatic eventration. Hiatal hernia was considered less likely because the cranially displaced stomach appeared to have been caudal to the diaphragm, rather than herniating (ie, type 1 sliding hiatal hernia or type 2 or 3 paraesophageal hiatal hernia) into the caudal mediastinum. Esophageal distention likely represented megaesophagus, for which a definitive underlying cause was not determined but could have included conditions such as esophagitis, neuromuscular dysfunction, and other causes. The differential diagnoses for the pulmonary abnormalities identified included atelectasis and pneumonia, particularly aspiration pneumonia.
Postcontrast sagittal (A) and dorsal (B) plane CT images of the thorax and cranial portion of the abdomen of the leopard in Figures 1 and 2. The left aspect of the diaphragm bulges cranially into the thorax, allowing cranial displacement of the entire stomach, pylorus, and proximal aspect of the descending duodenum, with associated mesentery. The esophagus is severely and diffusely distended with fluid (A and B) and gas (A). The right middle lung lobe has increased attenuation that effaces the pulmonary blood vessels and creates a lobar sign (arrowheads; B) and air bronchograms (arrows; B), consistent with consolidation. The liver is mildly enlarged (A). A—Image is displayed in a soft tissue window (slice thickness, 2 mm; window width, 320 HU; window level, 30 HU) with the leopard's head toward the left of the image. B—The image is displayed in a lung window (slice thickness, 2 mm; window width, 1,390 HU; window level, −124 HU) with the leopard's right toward the left of the image. D = Descending duodenum. E = Esophagus. H = Heart. L = Liver. Pa = Pancreas. Py = Pylorus. S = Stomach. T = Trachea.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Postcontrast sagittal (A) and dorsal (B) plane CT images of the thorax and cranial portion of the abdomen of the leopard in Figures 1 and 2. The left aspect of the diaphragm bulges cranially into the thorax, allowing cranial displacement of the entire stomach, pylorus, and proximal aspect of the descending duodenum, with associated mesentery. The esophagus is severely and diffusely distended with fluid (A and B) and gas (A). The right middle lung lobe has increased attenuation that effaces the pulmonary blood vessels and creates a lobar sign (arrowheads; B) and air bronchograms (arrows; B), consistent with consolidation. The liver is mildly enlarged (A). A—Image is displayed in a soft tissue window (slice thickness, 2 mm; window width, 320 HU; window level, 30 HU) with the leopard's head toward the left of the image. B—The image is displayed in a lung window (slice thickness, 2 mm; window width, 1,390 HU; window level, −124 HU) with the leopard's right toward the left of the image. D = Descending duodenum. E = Esophagus. H = Heart. L = Liver. Pa = Pancreas. Py = Pylorus. S = Stomach. T = Trachea.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Postcontrast sagittal (A) and dorsal (B) plane CT images of the thorax and cranial portion of the abdomen of the leopard in Figures 1 and 2. The left aspect of the diaphragm bulges cranially into the thorax, allowing cranial displacement of the entire stomach, pylorus, and proximal aspect of the descending duodenum, with associated mesentery. The esophagus is severely and diffusely distended with fluid (A and B) and gas (A). The right middle lung lobe has increased attenuation that effaces the pulmonary blood vessels and creates a lobar sign (arrowheads; B) and air bronchograms (arrows; B), consistent with consolidation. The liver is mildly enlarged (A). A—Image is displayed in a soft tissue window (slice thickness, 2 mm; window width, 320 HU; window level, 30 HU) with the leopard's head toward the left of the image. B—The image is displayed in a lung window (slice thickness, 2 mm; window width, 1,390 HU; window level, −124 HU) with the leopard's right toward the left of the image. D = Descending duodenum. E = Esophagus. H = Heart. L = Liver. Pa = Pancreas. Py = Pylorus. S = Stomach. T = Trachea.
Citation: Journal of the American Veterinary Medical Association 257, 7; 10.2460/javma.257.7.697
Treatment and Outcome
An exploratory laparotomy revealed that a thin membranous portion of the diaphragm formed an out-pouching into the thoracic cavity, consistent with diaphragmatic eventration. A section of the thin membranous portion of the diaphragm was resected, the resulting diaphragmatic defect was sutured closed, the esophageal hiatus was reconstructed, the esophagus was stabilized to the diaphragm with simple interrupted sutures, and a left-sided gastropexy was performed. The leopard recovered from anesthesia without complications and was discharged from the hospital the next day with prescriptions of tramadol (3.3 mg/kg, PO, q 12 h for 5 days), metoclopramide (0.50 mg/kg [0.23 mg/lb], PO, q 12 h for 14 days), maropitant (1.0 mg/kg [0.5 mg/lb], PO, q 24 h for 8 days), and omeprazole (1 mg/kg, PO, q 12 h for 30 days). Because of the risk of aspiration pneumonia, the owner was instructed to feed small, frequent meals of the patient's regular diet, monitor the leopard's resting respiratory rate, and call or return if its respiratory rate at rest was > 40 breaths/min. In addition, the owner was to monitor the incision site for excessive discharge or odor and to restrict the leopard's exercise for 14 days. The leopard was not returned for a postsurgical recheck examination; however, the owner reported that follow-up care was scheduled with the primary veterinarian.
Comments
Diaphragmatic eventration is rarely reported in veterinary medicine.5–9 It involves a thinning of the diaphragm that can be congenital or acquired and can involve a small region or an entire hemidiaphragm.6,9 The congenital form is characterized by muscular aplasia owing to incomplete ingrowth of muscle fibers between the pleural and peritoneal portions of the diaphragm during embryonic development.7,10 Acquired eventration is caused by phrenic neuropathy and resulting denervation atrophy of the diaphragm, which can occur secondary to trauma, inflammation, or invasive neoplasia.9 Given the young age of the leopard of the present report, congenital diaphragmatic eventration was considered most likely.
In the leopard of the present report, radiographic examination identified a diffuse esophageal abnormality and cranial displacement of the stomach, both of which could have explained a long-term history of clinical signs of regurgitation that could have been mistaken for vomiting. On the basis of radiographic findings, the differential diagnoses for cranial displacement of the stomach included hiatal hernia, diaphragmatic eventration, and gastroesophageal intussusception, among which there is substantial variation in terms of need for emergency surgical intervention, intraoperative surgical challenges, and prognosis. The use of CT allowed prioritization of diaphragmatic eventration because of the continuous nature of the diaphragmatic margin and absence of herniation of viscera into the caudal mediastinum. Thus, CT helped us rule out more serious conditions, such as gastroesophageal intussusception and visceral herniation with risk of strangulation and adhesions.
If CT had not been available, further diagnostic imaging to help characterize abnormal findings on radiography could have included ultrasonography, contrast radiography, or both. Ultrasonography has advantages of being noninvasive and commonly available in veterinary practice; however, technical challenges, such as gas in the stomach and gastrointestinal tract, may impair evaluation of the region of interest. Contrast radiography could have included esophagography or peritoneography. In this case, contrast esophagography was contraindicated because of our high concern for megaesophagus and risk of aspiration. The use of contrast peritoneography has previously been reported in a study11 evaluating diaphragmatic defects in golden lion tamarins and may have helped confirm diaphragmatic eventration in the leopard of the present report.
Computed tomography provided excellent anatomic detail that helped further clarify the underlying pathological details of the abnormal and complicated radiographic findings of the leopard of the present report. Findings in this leopard highlighted that, although rare, diaphragmatic eventration should be included on the differential diagnosis list for cranial displacement of the diaphragm and stomach in veterinary patients.
References
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