History
A 1.8-year-old 6.2-kg (13.7-lb) intact male Pug was evaluated due to chronic and progressive vomiting. Eight months prior to this presentation, the dog was diagnosed with a diaphragmatic hernia after experiencing frequent vomiting over a 2-week period. Initially, the dog vomited 1 or 2 times/wk, primarily at night; however, this frequency escalated to 12 times/d, including episodes with blood. The dog was unable to retain food or water without vomiting, particularly during activities such as ascending or descending stairs, leading to significant weight loss. The dog had no prior medical history or ongoing medications. Physical examination findings were unremarkable except for upper airway noises. Thoracic radiographs were obtained (Figure 1).
Lateral (A) and ventrodorsal (B) radiographic views of the thorax of a 1.8-year-old dog evaluated for chronic and progressive vomiting.
Citation: Journal of the American Veterinary Medical Association 2024; 10.2460/javma.24.05.0331
Radiographic Findings and Interpretation
Thoracic radiography revealed an oval, heterogeneous, soft tissue mass–like lesion with several gas lucencies in the caudodorsal aspect of the thoracic cavity in the lateral and ventrodorsal views (Figure 2). This abnormal soft tissue structure was partially superimposed on the midline of the diaphragm in both views. In the visible cranial abdomen, the spleen was not identified and the pylorus was normal in position, containing a small amount of gas. The cardiovascular and pulmonary structures and the pleural space appeared normal. Differential diagnoses included hiatal hernia (HH), esophageal mass (eg, paraesophageal empyema), an intraluminal esophageal foreign body, and a pulmonary mass.
Same radiographic views as in Figure 1. Notice the oval, heterogeneous, soft tissue mass–like lesion (white arrows) with gas lucency (black arrow). The mass-like lesion was partially superimposed on the midline of the diaphragm (arrowheads). The esophagus contains a small amount of gas just cranial to the lesion (black arrowhead).
Citation: Journal of the American Veterinary Medical Association 2024; 10.2460/javma.24.05.0331
Treatment and Outcome
The patient underwent surgeries to address brachycephalic obstructive airway syndrome, including nares resection, palatoplasty, and sacculectomy, along with HH repair involving left-sided gastropexy and esophagopexy as well as neutering. These were all performed the day after the radiographic examination. During surgery, the spleen and a cranial portion of the gastric fundus, which had herniated through the diaphragm without evidence of trauma, were noted. The dog recovered well from anesthesia and was monitored for respiratory distress, heavy breathing, or episodes of vomiting or regurgitation in the ICU overnight. The dog was discharged the following day for home care and monitoring.
Comments
Hiatal hernia involves the protrusion of abdominal contents through the esophageal hiatus into the thoracic cavity, which can be either congenital or acquired. Although 4 types of HH are described in human medicine, their clear identification solely by a conventional thoracic radiography is challenging. Type I HH, or sliding HH, is the most prevalent in dogs with brachycephalic obstructive airway syndrome.1 Type II HH, reported sporadically, involves the herniation of the gastric fundus alongside the normally positioned thoracic esophagus. Type III HH exhibits features of both type I and type II, whereas type IV HH involves herniation of various abdominal organs such as colon, spleen, pancreas, and small intestine.1,2 A previously case report3 has indicates possible correlations between brachycephalic dogs and type IV HH, where herniated organs included the stomach, the spleen, and the dorsal portion of the left lateral liver lobe.
The signalment, clinical symptoms, and radiographic findings were likely consistent with HH; however, the herniation of the spleen was an unexpected finding until surgery. This case underscores that soft tissue mass–like lesions on thoracic radiographs may primarily consist of abdominal organs other than the stomach, potentially leading to a secondary mild stomach hernia. This is indicated by the absence of the spleen in the visible abdominal portion and no displacement of the stomach.
Abdominal radiographs can be instrumental in assessing the location and displacement of the abdominal organs in patients with HH. Additionally, barium esophagram could aid in delineating the positional relationship between the esophagus and stomach and in detecting gastric displacement not apparent on conventional radiographs. Computed tomography would provide a more definitive diagnosis by identifying which organs were herniated and pinpointing the location of the hernia. Therefore, barium esophagram and CT examination would offer benefits for diagnosis by providing precise anatomic localization, assessing fluid accumulation of caudal esophagus and stomach, and determining the extent of herniated organs from the esophageal hiatus to the caudal mediastinum.4
In humans, although less common, massive type IV HH can lead to life-threatening respiratory complications through direct compression of mediastinal structures, a situation that might similarly impact dogs.5 Furthermore, gastric dilatation-volvulus (GDV), an acute life-threatening condition where the stomach rotates along its longitudinal axis causing gastric ischemia and obstructive shock, has been reported as a potential fatal complication of preexisting type II HH.1 Although other types of HH, including type IV HH, have not been mentioned in the context, having them could also increase the risk of GDV. Therefore, GDV should be considered in dogs presenting with any type of HH accompanied by acute abdominal pain and distention.
In conclusion, when HH is considered due to radiographic findings, the possibility of abdominal organs other than the stomach should be considered. Although rare, type II HH and potentially type IV HH should be recognized as potential causes due to the acute and severe complications they can engender. The use of advanced imaging modalities, such as barium esophagram and CT, would enable more accurate diagnoses of HH and provide a superior classification to that of radiography alone.
Acknowledgments
None reported.
Disclosures
The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.
Funding
The authors have nothing to disclose.
References
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