Feline abdominal ultrasonography: what’s normal? what’s abnormal? Hepatic vascular anomalies

Practical relevance: Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Although hepatic vascular anomalies are less common than disorders of the hepatic parenchyma and biliary tree, our understanding and recognition of these is gradually increasing with advancements in ultrasound technology and image quality. Clinical challenges: Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even differentiating between normal variation and pathological changes can be challenging for all but the most experienced. In addition, some views may be obscured by overlying structures; for example, the termination of a shunt entering the left phrenic or azygous veins is often difficut to see due to the high probability of lung passing between the shunt and the transducer as the cat breathes. Equipment: Ultrasound facilities are readily available to most practitioners, although use of ultrasonography as a diagnostic tool is highly dependent on operator experience. Aim: This review, part of an occasional series on feline abdominal ultrasonography, discusses the appearance of various hepatic vascular anomalies. It is aimed at general practitioners who wish to improve their knowledge and confidence in feline abdominal ultrasound and is accompanied by high-resolution images. Ultrasound of the liver and biliary tree were discussed in articles published in January and May 2019, respectively. Evidence base: Information provided in this article is drawn from the published literature and the author’s own clinical experience.