Practical relevance: Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the urinary tract provides important information useful in the investigation of several conditions including ureteral obstruction and cystitis.
Clinical challenges: Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as lipid droplets in the bladder, and pathological changes can be challenging.
Aim: This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased renal pelvis, ureters and urinary bladder. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. Ultrasound examination of the kidneys and perinephric space was discussed in an article published in May 2020.
Equipment: Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.
Evidence base: Information provided in this article is drawn from the published literature and the author's own clinical experience.
Keywords: Ultrasound; cystitis; cystocentesis; hydronephrosis; hydroureter; implantation; pyelectasia; urethral obstruction; urolith.