Computed Tomography Angiography Diagnosis of a Congenital Intrahepatic Central Divisional Portocaval Shunt in an Arabian Filly.
Abstract: A 1-month-old Arabian filly presented for central neurologic signs that developed shortly after birth. Hyperammonemia and elevated bile acids were identified, prompting abdominal computed tomography angiography (CTA) evaluation on suspicion of congenital portosystemic shunting (PSS). CTA revealed an anomalous vessel connecting the intrahepatic central divisional portal branch and caudal vena cava, with microhepatica and bilateral renomegaly. Necropsy confirmed a single, congenital, and intrahepatic central divisional portocaval shunt. Imaging literature addressing PSS in foals is sparse, with the current case representing the first instance in which CTA alone was fully diagnostic of an intrahepatic shunt in a foal.
© 2025 The Author(s). Veterinary Radiology & Ultrasound published by Wiley Periodicals LLC on behalf of American College of Veterinary Radiology.
Publication Date: 2025-09-25 PubMed ID: 40996890PubMed Central: PMC12463165DOI: 10.1111/vru.70091Google Scholar: Lookup
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Summary
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Overview
- A 1-month-old Arabian filly showed neurological symptoms likely due to a liver-related blood vessel abnormality.
- Advanced imaging (computed tomography angiography) identified a congenital portocaval shunt within the liver, which was later confirmed by necropsy.
Background and Clinical Presentation
- The filly displayed central neurological signs shortly after birth, indicating possible brain dysfunction.
- Laboratory tests revealed hyperammonemia (elevated blood ammonia) and increased bile acids, which often indicate liver dysfunction or abnormal blood flow through the liver.
- These signs raised suspicion of a congenital portosystemic shunt (PSS), a vascular anomaly where blood bypasses the liver’s filtration system.
Diagnostic Imaging and Findings
- Abdominal computed tomography angiography (CTA) was performed to evaluate the liver vasculature.
- CTA identified an anomalous vessel bridging the intrahepatic central divisional portal branch and the caudal vena cava.
- This anomaly is classified as a congenital intrahepatic central divisional portocaval shunt, meaning an abnormal intra-liver connection allowing portal blood to bypass liver processing.
- Additional imaging findings included microhepatica (smaller than normal liver size) and bilateral renomegaly (enlarged kidneys), which may be secondary to altered blood flow or systemic effects of the shunt.
Significance and Novelty
- Portosystemic shunts in foals, especially intrahepatic types, are rarely detailed in veterinary imaging literature.
- This case represents the first documented instance where CTA alone provided a complete and definitive diagnosis of an intrahepatic portocaval shunt in a foal.
- The case highlights the utility of CTA as a non-invasive, detailed imaging method capable of accurately diagnosing congenital vascular anomalies in equine patients.
Confirmatory Diagnosis
- Necropsy examination confirmed the presence of a single, congenital, intrahepatic central divisional portocaval shunt, validating the CTA findings.
- Such correlation between imaging and post-mortem findings strengthens confidence in CTA as an effective diagnostic tool for similar conditions.
Clinical Implications
- Early and accurate diagnosis of portosystemic shunts can guide treatment decisions and prognosis for affected foals.
- Awareness of this condition and advancement in imaging could lead to improved detection and management of congenital vascular anomalies in equine neonates.
Cite This Article
APA
Cournoyer N, Hostnik ET, Urion R.
(2025).
Computed Tomography Angiography Diagnosis of a Congenital Intrahepatic Central Divisional Portocaval Shunt in an Arabian Filly.
Vet Radiol Ultrasound, 66(6), e70091.
https://doi.org/10.1111/vru.70091 Publication
Researcher Affiliations
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA.
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA.
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA.
MeSH Terms
- Animals
- Female
- Computed Tomography Angiography / veterinary
- Horse Diseases / congenital
- Horse Diseases / diagnostic imaging
- Horses / abnormalities
- Portal Vein / abnormalities
- Portal Vein / diagnostic imaging
- Vena Cava, Inferior / abnormalities
- Vena Cava, Inferior / diagnostic imaging
Conflict of Interest Statement
The authors declare no conflicts of interest.
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