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11-month-old MN Hound Mix dog with an approximately 6 week history of weight loss, and more recent (3-4 day) history of lethargy and anorexia.
The dog was adopted from South Carolina as a puppy 6 months ago. Routine blood work at the time of adoption showed mild elevations in ALT and ALP. These elevations were noted to be progressively elevated at the time when the weight loss was noted approximately 6 weeks prior to presentation. An abdominal ultrasound performed at the referring practice showed severe, diffuse dilation of the intrahepatic biliary tree (images unavailable). Three days before presentation, the patient became completely anorexia and had multiple episodes of regurgitation.


Non-enhanced CT of the abdomen

CT post-contrast in transverse plane and dorsal reconstruction

-Multiple organs herniated into the caudal thorax to the right of midline, all to the right of the vena cava. Herniated organs include the pyloroduodenal junction as well as much of the duodenum and pyloric antrum of the stomach.
-Major duodenal papilla is within the hernia, with severe dilation of the common bile duct, cystic duct, and intrahepatic bile ducts.
-Abrupt narrowing of the caudal vena cava as it enters the caval foramen
-Distention of the hepatic veins throughout the liver
-Multiple anomalous vessels surround the caudal vena cava as it passes through the foramen, in a portion of herniated abdominal fat. These anomalous vessels are continuous with a severely enlarged azygous vein cranially.
-Second cluster of anomalous vessels communicating with the left renal vein and travel caudal to the left kidney
-Small mineral foreign body in the gastric lumen

1. Right-sided diaphragmatic hernia containing stomach, duodenum, common bile duct, right limb of the pancreas, and likely a portion of the right liver. The hernia is prioritized to represent an acquired/traumatic hernia, though a congenital hernia involving the caval foramen is also possible.
2. Extrahepatic biliary obstruction and likely some degree of proximal gastrointestinal obstruction, presumed secondary to the above.
3. Acquired collateral vessels at the level of (and perhaps within) the hernia continuous with an enlarged azygous vein, consistent with a partial obstruction of the caudal vena cava secondary to the hernia.
4. Left splenogonadal portosystemic shunt, likely related to a degree of postsinusoidal obstruction of blood flow related to the above. No other evidence of portal hypertension is identified on this exam (ascites, gallbladder wall or pancreatic edema, etc.)
5. Small mineral gastric foreign body

CONCLUSIONS: An abdominal explore and caudal sternotomy were performed, and revealed a large, likely congenital hernia secondary to a severely enlarged caval foramen. At the time of surgery, the duodenum, pancreas, mesentery and right kidney were herniated into the thorax. The intrahepatic and extrahepatic bile ducts were severely enlarged. The organs were reduced back into the abdomen and the defect in the diaphragm was closed as much as possible. The patient recovered well from anesthesia and all clinical signs resolved after 3 days in the hospital. The patient was eating well upon discharge, and was lost to follow-up.



  1. Kim J, Kim S, Jo J, Lee S, Eom K. Radiographic and computed tomographic features of caval foramen hernias of the liver in 7 dogs: mimicking lung nodules. J Vet Med Sci 2016; 78 (11): 1693-1697
  2. Park J, Lee HB, Jeong SM. Caval foramen hernia in a dog: Preoperative diagnosis and surgical treatment. J Vet Med Sci 2020; 82 (1): 1602-1606


Surgical images. Cranial is on top.