The utility of clinicopathological findings and point-of-care ultrasound in increasing the index of suspicion of ureteral obstruction in azotaemic cats presenting to the emergency room.

OBJECTIVES: Ureteral obstruction is a common post-renal cause of azotaemia in cats. The objective of this study was to describe clinicopathological and point-of-care ultrasound findings in azotaemic cats that may increase the index of suspicion of ureteral obstruction. MATERIALS AND METHODS: A retrospective case-control study was conducted of azotaemic cats presenting to the emergency room of a referral teaching hospital. Cats were included if they were azotaemic and had point-of-care ultrasound and formal ultrasound performed. Cats were grouped into obstructed and non-obstructed groups based on formal specialist ultrasound and pyelography. Point-of-care ultrasound findings were described, including renal size and symmetry, renal pelvis dilation, perinephric fluid, and visualisation of the proximal ureter or calculi. Univariate analysis was performed to identify historical, biochemical and point-of-care ultrasound findings associated with ureteral obstruction before multivariate analysis. RESULTS: One hundred twenty-two azotaemic cats met the inclusion criteria. Seventy-four cats were included in the obstructed azotaemic group and 48 cats in the non-obstructed azotaemic groups. Point-of-care ultrasound abnormalities were detected in 60 of 74 (81.1%) obstructed cats and 18 of 48 (37.5%) non-obstructed cats. Renal pelvis dilation (odds ratio 38.8; 95% confidence interval 2.9 to 515), hyporexia (odds ratio 5.9; 95% confidence interval 1.15 to 30.13), hypercalcaemia (odds ratio 16.6; 95% confidence interval 1.2 to 223.0) and hypokalaemia (odds ratio 21.7; 1.33 to 354.62) were more likely to be associated with ureteral obstruction than non-obstructive disease. CLINICAL SIGNIFICANCE: Point-of-care ultrasound abnormalities are documented frequently in azotaemic cats with ureteral obstruction. Cats with renal pelvis dilation were 39 times more likely to have ureteral obstruction than non-obstructive acute kidney injury.

Survival and complications in cats treated with subcutaneous ureteral bypass.

OBJECTIVES: To report the complications and factors affecting outcome for cats following placement of a subcutaneous ureteral bypass (SUB™). MATERIALS AND METHODS: In this retrospective study, complications, the presence of a urinary tract infection and survival time were recorded following subctutaneous ureteral bypass placement. Factors affecting survival time were assessed using a Kaplan Meier curve and log rank test. RESULTS: Ninety-five cats had 130 subcutaneous ureteral bypasses placed. Ten cats did not survive to discharge. Forty cats died or were euthanised after discharge (42%); the median survival time of these cats was 530 days (range 7 to 1915). Minor complications occurred in 18 cats (19%) and major complications occurred in 46 cats (48%), the majority of which were after hospital discharge. Twenty-seven cats were diagnosed with a urinary tract infection (UTI) post-operatively. A significant association between long-term survival and creatinine at presentation was identified. The median survival time for cats presenting with creatinine concentration ≥440 µmol/L (International Renal Interest Society stage acute kidney injury (AKI) 4 and 5) was 530 days (95% CI 273-787 days), compared to a median survival time of 949 days (95% CI 655-1243 days; Log Rank P=0.024) for those cats presenting with creatinine <440 µmol/L (International Renal Interest Society stage AKI 1-3). CLINICAL SIGNIFICANCE: In this population of cats, subcutaneous ureteral bypass placement was associated with an approximately 10% in-hospital mortality and a high complication rate. Most complications were manageable, resulting in an overall median survival time of over 2 years.

CT findings in dogs with gastric malposition: 6 cases (2016-2019).

OBJECTIVES: To describe the computed tomographic (CT) findings of gastric malposition in a group of dogs with suspected chronic gastric instability. MATERIALS AND METHODS: A multicentre retrospective study of CT studies of dogs with abnormal gastric position in the absence of clinical signs referable to gastric dilatation and volvulus. RESULTS: Gastric malposition was identified in six dogs as either an incidental finding or in dogs with histories of chronic and intermittent gastroenteropathy. Gastric malposition was similar in all six cases; the pyloric canal was positioned in the left cranial abdomen in close proximity to the cardia and the pyloric antrum was found either to the left or ventral to the fundus. CLINICAL SIGNIFICANCE: Recognition of gastric malposition as an incidental or chronic finding may prevent unnecessary emergency intervention on patients presenting for unrelated conditions.

Diagnostic imaging observations in cats treated with the subcutaneous ureteral bypass system.

OBJECTIVES: To describe pre- and post-operative ultrasonographic and fluoroscopic findings, including any abnormalities, in cats treated for ureteral obstruction with a subcutaneous ureteral bypass system. METHODS: Retrospective review of imaging findings in cats with ureteral obstruction that had surgery to place the first version of the bypass system and at least one follow-up ultrasound or fluoroscopic study. Pre- and post-operative renal pelvic diameter on ultrasound, fluoroscopic appearance of the bypass system and any related abnormality were recorded. RESULTS: Eighty-one cats were included (47 unilateral, 34 bilateral bypass systems). Median preoperative renal pelvic diameter was 9 mm (range 3 to 28 mm) and median renal pelvic diameter at the first postoperative ultrasound was 3 mm (range 2 to 23 mm). The median number of postoperative imaging studies was two (range 1 to 8) and the median follow-up period after surgery was 205 days (range 1 to 1378 days). Bypass system abnormalities were identified postoperatively in 43 (53%) cats, including nephrostomy or cystostomy catheter blockage due to an undetermined cause or kinking of the catheter, nephrostomy or cystostomy catheter leakage, non-obstructive kinking of the catheter and loose nephrostomy pig-tail loop. Many abnormalities required repeat surgery, but others were managed conservatively. Fifty-four percent of obstructed ureters became patent after bypass placement, although the majority remained slightly dilated or had irregular margins compatible with chronic inflammation. CLINICAL SIGNIFICANCE: Bypass abnormalities, mainly tube blockage, occurred frequently in cats treated for ureteral obstruction. Ultrasonography and fluoroscopy were useful for postoperative examination, including documenting renewed ureteral patency and investigation of suspected abnormalities.

Use of dual-phase contrast computed tomography for evaluation of the normal canine male genital tract.

OBJECTIVES: To evaluate the use of dual-phase contrast-enhanced computed tomography for the depiction of the features of the male genital tract, highlighting differences between entire and neutered dogs. METHODS: Computed tomography exams of 23 entire and 23 neutered male dogs with no history of urogenital disease were included in this retrospective study, with exams acquired pre-, 30 and 98·9 ±27·4 seconds after intravenous contrast administration. The genital structures were subjectively evaluated for visibility, contrast enhancement and enhancement pattern and differences between entire and neutered dogs were described. Objective measurements of attenuation and size of the prostatic tissue were acquired. RESULTS: The root, body and glans of the penis could be evaluated in all dogs and appeared larger in entire dogs, though objective measurements could not be reliably made because these structures are small and curved. There was contrast enhancement of the cavernous structures, most reliably in the bulb and corpus spongiosum and most frequently in entire dogs in the delayed post-contrast phase. In entire dogs, the small testicular vessels most commonly had a vermiform shape in the early post-contrast phase, and a homogeneous appearance in the delayed phase. Sternal recumbency with the coxofemoral joints extended improved visibility of the genital structures. CLINICAL SIGNIFICANCE: Dual-phase contrast-enhanced computed tomography is useful for depiction of the structures of the male genital tract, with the early phase especially highlighting the vascular and the delayed phase the cavernous structures.