MRI characteristics of canine prostatic neoplasia.

Magnetic resonance imaging (MRI) has been used to evaluate dogs with suspected prostatic neoplasia, however, published studies describing MRI characteristics of canine prostatic neoplasia are currently lacking. The aims of the current retrospective case series study were to describe MRI findings of the pelvic region in dogs with a histopathologic or cytologic diagnosis of prostatic neoplasia. Retrospective analysis of these images was then performed by a board-certified veterinary radiologist for shared imaging characteristics. The most consistent characteristics were heterogeneous hyperintensity of the tumor on T2-weighted images (10/10) and short tau inversion recovery images (10/10), prostatic capsular margin distortion by the tumor (10/10), cavitations (10/10), complete effacement of the prostatic architecture (9/10), neurovascular bundle (NVB) compression or invasion (9/10), heterogeneous isointensity of the tumor on T1-weighted images (9/10), and strong contrast enhancement of the tumor (8/10). Additional features included an overlying pattern of distorted radiating striations (7/10), regional lymphadenomegaly (5/10), mineralization within the mass (5/10), urinary bladder trigone involvement (6/10), and post-prostatic urethral involvement (7/10). These findings supported the use of MRI as an adjunct imaging modality for diagnosis and therapeutic planning of prostatic neoplasia and including prostatic neoplasia as a likely differential diagnosis for dogs with these MRI characteristics.

NEOURETEROCYSTOSTOMY AND URETHRAL STENT PLACEMENT IN A BLACK-HANDED SPIDER MONKEY (ATELES GEOFFROYI).

A 27-y-old female black-handed spider monkey (Ateles geoffroyi) was evaluated 13 d after an ovariohysterectomy because of abdominal distension, anorexia, and absent urination. The animal was diagnosed with a uroabdomen and urethral obstruction from computed tomographic findings and fluid creatinine levels. During exploratory laparotomy, a defect in the right ureter was confirmed as the source of the uroabdomen. Utilizing intraoperative fluoroscopy, a urethral obstruction with an irregular luminal filling defect was evident. A self-expanding nitinol urethral stent was placed, and a ureteral transposition was performed. Two months after the procedure, the animal developed dysuria, a urinary tract infection, recurrent bladder distension and a partial urethral obstruction. Treatment with prazosin 1 mg/kg PO q12h improved urination. Reobstruction of the urethra occurred 17 mo postsurgery, and the animal was euthanatized. On postmortem examination, the animal had ingrowth into the stent with proliferative granulation tissue, detrusor muscle degeneration, pelvic adhesions, cystitis, pyelonephritis, and hydronephrosis.

Use of an Absorbable Urethral Stent for the Management of a Urethral Stricture in a Stallion.

OBJECTIVE: To describe the successful management of a urethral stricture with an absorbable stent in a stallion. STUDY DESIGN: Clinical report. ANIMALS: Stallion with a urethral stricture. RESULTS: A 12-year-old Thoroughbred breeding stallion was evaluated for acute onset of colic. Uroperitoneum because of presumptive urinary bladder rupture, with urethral obstruction by a urethrolith, was diagnosed. The uroperitoneum was treated conservatively. The urethrolith was removed through a perineal urethrotomy. Approximately 15 weeks after urethrolith removal, the stallion presented with a urethral stricture. The stricture was unsuccessfully treated with an indwelling urinary catheter and 4 attempts at balloon dilation. Eight weeks after diagnosis of stricture, an absorbable polydioxanone (20 mm × 80 mm) urethral stent was implanted under percutaneous, ultrasound guidance. Urethroscopy was performed at 70, 155, and 230 days after stent placement and the endoscope passed through the affected site without complication. Urethroscopy at 155 days showed the stent had been reabsorbed. Follow-up 20 months after stent placement reports the stallion was able to void a normal urine stream. CONCLUSIONS: Absorbable urethral stent placement was a feasible treatment for urethral stricture in this stallion.

Efficacy of Two Radiologic-Assisted Prophylactic Gastropexy Techniques.

OBJECTIVE: To describe the technique and clinical outcome of prophylactic percutaneous radiologic-assisted gastropexy (PRG) and radiologic-assisted incisional gastropexy (RIG) in client-owned dogs. STUDY DESIGN: Prospective, nonrandomized clinical trial. ANIMALS: Fourteen client-owned, large, and giant breed dogs. METHODS: Four dogs underwent PRG with fluoroscopic guidance to place 2 T-fasteners into the pyloric antrum and secure it to the right body wall. Ten dogs underwent RIG, which was a modification of PRG. For RIG, the T-fasteners were first used to approximate the pyloric antrum and body wall, then a full thickness incision through the body wall was made and the pyloric antrum was sutured to the internal abdominal wall. The duration and complications of each procedure were recorded. The gastropexy was assessed by abdominal ultrasound at day 1, week 2, and week 8 postoperative and by barium gastrogram at week 8 postoperative. RESULTS: No dogs undergoing PRG had a gastropexy present at week 2. All dogs undergoing RIG had ultrasonographic evidence of gastropexy at day 1, week 2, and week 8 postoperative. Gastrograms in 9/9 dogs were consistent with an intact gastropexy, appropriate gastric positioning and appropriate gastric emptying began. No major complications were noted. CONCLUSION: The PRG was unsatisfactory and did not result in a permanent gastropexy. The RIG was safe and created a gastropexy that remained intact at 8 weeks postoperative. The RIG should be considered as a minimally invasive option for prophylactic gastropexy in dogs of at-risk breeds.

Description and Biomechanical Comparison of a Percutaneous Radiologic Gastropexy Technique in a Canine Cadaver Model.

OBJECTIVE: To describe a novel percutaneous radiologic gastropexy (PRG) technique in a canine model and to biomechanically compare this technique to open incisional gastropexy (OIG) and laparoscopic-assisted incisional gastropexy (LAG). STUDY DESIGN: Randomized ex vivo biomechanical study. ANIMALS: Canine cadavers. METHODS: Fifteen cadavers were randomized to 1 of 3 surgical interventions: OIG, LAG, and PRG. For the PRG procedure, the stomach was distended with air, and a preloaded T-fastener device was utilized to attach the stomach to the body wall with fluoroscopic-guidance. The procedural times of the 3 techniques were recorded. After completion of the procedure, the stomach and body wall overlying the stomach wall were harvested and the maximum tensile strength of the gastropexies was determined. RESULTS: The maximal tensile strength was not significantly different between groups. The total procedural time for the PRG procedure (5 minutes) was significantly shorter than both OIG (28 minutes) and LAG (20 minutes) procedures. CONCLUSION: The PRG technique described in this study demonstrated a similar maximal tensile strength to commonly employed gastropexy techniques (OIG and LAG) in an acute canine model. Additionally, the PRG procedure was significantly faster to perform. The clinical relevance of this technique will be determined by further study to assess the applicability and efficacy of this procedure in clinical patients by determining the likelihood of adhesion development and the ability of the adhesion to prevent gastric volvulus.

Percutaneous ureteral stent placement for the treatment of a benign ureteral obstruction in a Sumatran tiger (Panthera tigris sumatrae).

A 15-year-old, 113 kg intact male Sumatran tiger (Panthera tigris sumatrae) was evaluated for weight loss, polydipsia, and intermittent hematuria. The tiger was immobilized for diagnostic testing including blood work, urinalysis, and abdominal ultrasound. Laboratory testing demonstrated macro- and microhematuria, azotemia, and an increased urine protein:creatinine ratio. Abdominal ultrasound revealed bilateral ureterolithiasis as well as hydronephrosis and ureteral dilation. Ultrasonography performed 5 months later revealed worsening of the right-sided hydronephrosis and hydroureter and a decrease in the severity of dilation on the left side presumably from passage of the left-sided ureteral calculi. Nephroureteral decompression via the placement of a stent was elected. A pigtail ureteral catheter (8.2 French diameter) was placed in the right ureter via an antegrade percutaneous approach utilizing ultrasound and fluoroscopic-guidance. Following stent placement, macrohematuria resolved although microhematuria was noted in opportunistic urine samples. Five months after stent placement, the azotemia had mildly progressed, the urine protein:creatinine ratio was improved, the right hydronephrosis and hydroureter had completely resolved, and the ureteral stent remained in the appropriate position. The tiger had clinically improved with a substantial increase in appetite, weight, and activity level. Ureteral stenting allowed for nephroureteral decompression in the captive large felid of this report, and no complications were encountered. Ureteral stenting provided a minimally invasive method of managing ureteral obstruction in this patient and could be considered in future cases due to the clinical improvement and low morbidity.

Case report: Chylopericardium secondary to dialysis catheter related jugular venous thrombosis in two dogs receiving long-term hemodialysis.

Chylopericardium is a rare entity in veterinary medicine. In this report we document the development of chylopericardium in two dogs undergoing chronic hemodialysis. An 11-year-old female spayed Labrador retriever (Case 1) presented with acute coughing and lethargy 2 months following initial dialysis catheter placement and initiation of dialysis therapy for severe azotemia. Echocardiography demonstrated severe pericardial effusion and cardiac tamponade. Pericardial fluid analysis was consistent with chylous effusion. The dog underwent a subtotal pericardiectomy with thoracic duct ligation, and a PleuralPort™ was placed. The patient continued to receive outpatient hemodialysis therapy after pericardiectomy for several months until she died acutely at home. A 4-year-old male neutered Doberman (Case 2) was being treated for 2 months with outpatient hemodialysis for management of chronic kidney disease. On presentation for the 17th hemodialysis treatment, the patient had increased respiratory rate. Echocardiography demonstrated pleural and pericardial effusions, and fluid analysis in both cavities was consistent with chylous effusion. Use of tissue plasminogen activator (TPA), clot removal and replacement of the catheter was attempted; however pleural and pericardial effusion continued. The patient was euthanized after 25 hemodialysis sessions as owners elected not to pursue more procedures. In both cases, the cause of the chylopericardium was suspected to be secondary to catheter-associated thrombosis and/or stenosis based on multiple imaging modalities. Despite use of rivaroxaban and clopidogrel concurrently in each case, the chylous effusion persisted. This case report describes clinical details of a rare complication of long-term indwelling dialysis catheters in two dogs.

Bilateral external jugular vein anomalies preventing hemodialysis catheter placement in a cat with anuria secondary to Lilium species intoxication.

Case series summary: A 2-year-old female spayed Abyssinian cat was evaluated for lethargy and inappetence that first occurred approximately 4 days prior. In addition, urination had not been observed by the owner for 5 days. A Lilium species plant had been brought into the house approximately 5 days before initial evaluation, and intoxication was therefore suspected. Bloodwork revealed anemia, severe azotemia and hyperkalemia. As the cat was anuric with severe azotemia, hyperkalemia and fluid overload, intermittent hemodialysis was recommended. Attempts were made to place a hemodialysis catheter into the external jugular veins bilaterally, but after initial successful venipuncture, the instrumentation would not pass into either vein. During fluoroscopic angiography, no internal jugular veins or external jugular veins caudal to the thoracic inlet were visualized and venous drainage from the head occurred via the vertebral veins. Owing to the anomalous anatomy in the cervical region, a hemodialysis catheter could not be placed into either jugular vein. Alternative sites for the placement of an extracorporeal catheter were discussed with the owner, but humane euthanasia was elected. Relevance and novel information: To the authors' knowledge, this is the first report of a cat with bilateral external jugular vein anomalies resulting in blind endings that did not communicate with the vena cava. This was discovered during attempts to place a hemodialysis catheter for the management of anuric renal failure secondary to Lilium species intoxication. While this anatomical variation is likely uncommon, it is an important differential to consider when faced with challenging external jugular vein catheterizations in feline patients.

A 20-year scoping review of the veterinary interventional radiology and interventional endoscopy literature (2000-2019).

BACKGROUND: Interventional radiology (IR) and interventional endoscopy (IE) have broad potential for minimally invasive therapy in veterinary patients, but the scope of original peer-reviewed veterinary IR/IE research publications has not been described. OBJECTIVES: Catalogue published applications and indications for noncardiac therapeutic IR/IE in animals and describe type and quality of veterinary IR/IE research over 20 years. METHODS: Highly-cited veterinary journals were searched to identify articles published 2000 to 2019 involving therapeutic IR/IE applications for clinical veterinary patients. Articles were assigned a level of evidence (LOE) according to published standards. Authorship, animal data, study design, and interventions were described. Change in publication rate, study size, and LOE of IR/IE articles over time was analyzed. RESULTS: One hundred fifty-nine of 15 512 (1%) articles were eligible, including 2972 animals. All studies were low LOE and 43% were case reports with ≤5 animals. Number of IR/IE articles per year (P < .001), proportion of journals' articles pertaining to IR/IE (P = .02), and study size (P = .04) all increased over time, but LOE (P = .07) did not. Common target body systems were urinary (40%), digestive (23%) respiratory (20%), and vascular (13%). Common indications were nonvascular luminal obstructions (47%), object retrieval (14%), and congenital anomalies (13%). Most procedures involved indwelling medical devices or embolic agents, whereas tissue resection and other procedures were less common. Procedures utilized fluoroscopy (43%), endoscopy (33%), ultrasound (8%), digital radiography (1%), or fluoroscopy in combination with other modalities (16%). CONCLUSIONS: Treatments involving IR/IE have wide applicability in veterinary medicine but large, rigorous, and comparative studies describing these procedures are lacking.

Ultrafiltration during intermittent hemodialysis in dogs with acute kidney injury.

BACKGROUND: Ultrafiltration is performed to alleviate fluid overload in dogs with acute kidney injury (AKI) undergoing intermittent hemodialysis (IHD). OBJECTIVES: To describe prescription patterns for ultrafiltration in dogs receiving IHD for AKI and risk factors for ultrafiltration-related complications. ANIMALS: Seventy-seven dogs undergoing 144 IHD treatments between 2009 and 2019. METHODS: Medical records of dogs receiving IHD for AKI were reviewed. The initial 3 IHD treatments in which ultrafiltration was prescribed were included. Ultrafiltration-related complications were defined as those requiring an intervention such as transient or permanent discontinuation of ultrafiltration. RESULTS: Mean fluid removal rate per treatment was 8.1 ± 4.5 mL/kg/h. Ultrafiltration-related complications occurred in 37/144 (25.7%) of treatments. Hypotension was rare (6/144, 4.2% of treatments). No ultrafiltration-related complications resulted in deaths. The mean prescribed fluid removal rate per treatment was higher in dogs with ultrafiltration-related complications than without (10.8 ± 4.9 mL/kg/h vs 8.8 ± 5.1 mL/kg/h, respectively; P = .03). The mean delivered fluid removal rate per treatment was significantly lower in dogs with UF-related complications compared to those without complications (6.8 ± 4.0 mL/kg/h vs 8.6 ± 4.6 mL/kg/h, respectively; P = .04). Variables associated with ultrafiltration-related complications (P < .05) included central venous oxygen saturation, body temperature before IHD treatment, total extracorporeal circuit volume and BUN at the end of IHD treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Ultrafiltration during IHD in dogs with AKI is overall safe. Higher prescribed ultrafiltration rates were associated with increased risk of complications. Decrease in central venous oxygen saturation is associated with ultrafiltration-related complications, emphasizing the utility of in-line blood monitoring.

Diagnosis, management, and outcome of urethral obstruction secondary to the capsule associated with the artificial urethral sphincter device.

BACKGROUND: Urethral obstruction secondary to artificial urethral sphincter (AUS) implantation is a recognized complication in dogs. However, urethral obstruction secondary to AUS-associated capsule formation has been described rarely. HYPOTHESIS: Describe clinical and diagnostic findings, management, and outcome in 6 dogs with urethral obstruction secondary to AUS-associated capsule formation. ANIMALS: Six client-owned dogs. METHODS: Retrospective study. Medical records between January 1, 2010, and June 30, 2021, were reviewed to identify dogs with urethral obstruction associated with the AUS device. RESULTS: The AUS device was implanted a median of 884 days (range, 20-2457 days) before presentation for urethral obstruction. Median age at time of urethral obstruction was 4.7 years (range, 3.1-8.7 years). Clinical signs at the time of urethral obstruction were stranguria (n = 4), pollakiuria (3), weak urine stream (2), and worsened urinary incontinence (1). In all dogs, the urethra was noted to be stenotic during urethroscopy and positive contrast cystourethrography. All dogs underwent surgery, and a fibrous capsule associated with the AUS was found to be causing urethral stenosis. Resolution of urethral obstruction occurred in all dogs after transection or removal of the capsule. Positive bacterial cultures were obtained from the capsule, AUS, or both in all dogs. Recurrence of urethral obstruction had not occurred in any dog at the time of follow-up. CONCLUSIONS AND CLINICAL IMPORTANCE: Urethral obstruction secondary to capsule formation is an uncommon but clinically important complication associated with use of the AUS. Continued investigation is needed to evaluate this complication more thoroughly, and its possible association with infection.

Effect of standard-dose and high-dose pimobendan on select indices of renal and cardiac function in dogs with American College of Veterinary Internal Medicine stage B2 myxomatous mitral valve disease.

BACKGROUND: Pimobendan might have favorable effects on renal function but this has not been well-studied in dogs with myxomatous mitral valve disease (MMVD). OBJECTIVES: Determine the effects of standard-dose (SD_pimo) and high-dose pimobendan (HD_pimo) on glomerular filtration rate (GFR) and cardiac size and function in dogs with preclinical MMVD. ANIMALS: Thirty nonazotemic dogs with stage B2 MMVD. METHODS: Prospective, randomized, double-blinded, placebo-controlled clinical study. Dogs had an echocardiographic examination, assessment of GFR (iohexol clearance), N-terminal probrain natriuretic peptide (NT-proBNP), and quality of life (QOL) score at baseline and 7 to 10 days after placebo (n = 6), SD_pimo 0.2 to 0.3 mg/kg q12 (n = 12), or HD_pimo 0.5 to 0.6 mg/kg q12h (n = 12). RESULTS: No significant differences in GFR or QOL scores were detected between groups (P ≥ .07). After HD_pimo, the mean [SD] percent change of NT_proBNP (-46.1 [20.2]%), left atrial volume (LAV; -27.1 [16.9]%), left ventricular end-diastolic volume (EDV; -21.8 [15.0]%), and end-systolic volume (ESV; -55.0 [20.7]%) were significantly different (P ≤ .004) from placebo (0.5 [19.9]%, 1.3 [15.6]%, -0.2 [8.2]%, -7.3 [35.6]%, respectively) but not the percent change after SD_pimo (-36.6 [16.1]%, -22.7 [14.9]%, -16.7 [12.5]%, -41.6 [14.8]%, respectively; P > .05). After SD_pimo, percent change of NT_proBNP, LAV, EDV, and ESV were significantly different from placebo (P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE: Results suggest that pimobendan (SD_pimo or HD_pimo) might not affect renal function in nonazotemic dogs with stage B2 MMVD. High-dose pimobendan did not demonstrate advantages over SD_pimo within the constraints of our study.

Untargeted Metabolomics Identify a Panel of Urinary Biomarkers for the Diagnosis of Urothelial Carcinoma of the Bladder, as Compared to Urolithiasis with or without Urinary Tract Infection in Dogs.

Urothelial carcinoma (UC), the most common urologic cancer in dogs, is often diagnosed late because the clinical signs are shared by other non-malignant lower urinary tract disorders (LUTD). The urine-based BRAFV595E test for UC is highly effective only in certain breeds; hence additional non-invasive biomarkers of UC are needed. Here, urine from dogs with UC (n = 27), urolithiasis (n = 8), or urolithiasis with urinary tract infection (UTI) (n = 8) were subjected to untargeted metabolomics analyses, using GC-TOF-MS for primary metabolites, QTOF-MS for complex lipids, and HILIC-QTOF MS for secondary and charged metabolites. After adjusting for age and sex, we identified 1123 known metabolites that were differentially expressed between UC and LUTD. Twenty-seven metabolites were significant (1.5 ≤ log2FC ≤ −1.5, adjusted p-value < 0.05); however, 10 of these could be attributed to treatment-related changes. Of the remaining 17, 6 (hippuric acid, N-Acetylphenylalanine, sarcosine, octanoylcarnitine, N-alpha-methylhistamine, glycerol-3-galactoside) discriminated between UC and LUTD (area under the ROC curve > 0.85). Of the 6 metabolites, only hippuric acid and N-alpha-methylhistamine were discriminatory in both male (n = 20) and female (n = 23) dogs, while sarcosine was an effective discriminator in several breeds, but only in females. Further investigation of these metabolites is warranted for potential use as non-invasive diagnostic biomarkers of dogs with UC that present with LUTD-related clinical signs.

Outcome of dogs with bone marrow suppression secondary to Sertoli cell tumour.

Sertoli cell tumours are one of the most common canine testicular neoplasia. These tumours are significantly more likely to arise in cryptorchid dogs and are often functional, oestrogen-secreting tumours which can lead to fatal myelotoxicity. The goal of this study was to describe the outcome of dogs with oestrogen-induced bone marrow suppression secondary to Sertoli cell tumours in seven client-owned dogs. Medical records from April 1, 2011 through April 1, 2021 were reviewed to identify dogs that underwent surgical management of a Sertoli cell tumour with documented bone marrow suppression. Overall, 5/7 dogs required transfusion of blood products peri-operatively. Cases 1 and 6 received a transfusion of packed red blood cells (RBC) prior to surgery and case 5 required a transfusion of whole blood. Case 1 also required a transfusion of platelets before surgery. Post-operatively, cases 1 and 2 received packed RBC's and case 6 received two transfusions of whole blood. Case 3 required transfusions of both fresh frozen plasma and platelets post-operatively. All dogs survived to discharge and 6/7 dogs had documented improvement in haematopoietic values. Two dogs remained chronically thrombocytopenic. The median hospital stay was 4 days. One dog died within 4 weeks of surgery from worsening pancytopenia. Survival for greater than 1 year was documented in 4/7 dogs, and one dog was lost to follow-up 4 months post-operatively. One dog remained severely pancytopenic 4 weeks post-operatively and received oral lithium treatment. Improvements in all blood cell lines were observed within the 4 weeks and resolution of pancytopenia within 6 weeks. Historically, the prognosis for dogs with bone marrow suppression secondary to Sertoli cell tumours was guarded to poor. This report documented improved outcomes for dogs that underwent surgery, including one dog that received lithium chloride as treatment for Sertoli cell tumour-induced bone marrow suppression.

Urolithiasis in dogs: Evaluation of trends in urolith composition and risk factors (2006-2018).

BACKGROUND: Urolithiasis is a common and often recurrent problem in dogs. OBJECTIVE: To evaluate trends in urolith composition in dogs and to assess risk factors for urolithiasis, including age, breed, sex, neuter status, urolith location, and bacterial urolith cultures. SAMPLE POPULATION: A total of 10 444 uroliths and the dogs from which they were obtained. METHODS: The laboratory database at the UC Davis Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from dogs between January 2006 and December 2018. Mineral type, age, breed, sex, neuter status, urolith location, and urolith culture were recorded. Trends were evaluated and variables compared to evaluate risk factors. RESULTS: Calcium oxalate (CaOx) and struvite-containing uroliths comprised the majority of all submissions from dogs, representing 47.0% and 43.6%, respectively. The proportion of CaOx-containing uroliths significantly decreased from 49.5% in 2006 to 41.8% in 2018 (P = .006), with no change in the proportion of struvite-containing urolith submissions. Cystine-containing uroliths comprised 2.7% of all submissions between 2006 and 2018 and a significant nonlinear increase in this mineral type occurred over time (1.4% of all submissions in 2006 to 8.7% in 2018; P < .001). Of all cystine-containing uroliths, 70.3% were from intact male dogs. Age, breed, and sex predispositions for uroliths were similar to those previously identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Although calcium oxalate- and struvite-containing uroliths continue to be the most common uroliths submitted from dogs, a decrease in the proportion of CaOx-containing uroliths and an increase in the proportion of cystine-containing uroliths occurred during the time period evaluated.

Stenting of Malignant Urinary Tract Obstructions in Humans and Companion Animals.

Urine retention secondary to neoplastic obstructions of the upper and lower urinary tracts is a life-threatening condition in both humans and companion animals. Stents can be placed to temporarily or permanently open obstructed urinary tract lumens and are often able to be placed using minimally invasive techniques with guidance via ultrasonography or fluoroscopy. The literature for these techniques is vast for humans and growing for companion animals. The below review provides a discussion of the principles of stenting and types of ureteral and urethral stents, as well as the techniques for placing these stents in humans and companion animals.

Urolithiasis in cats: Evaluation of trends in urolith composition and risk factors (2005-2018).

BACKGROUND: Urolithiasis is an important upper and lower urinary tract disease in cats that results in morbidity and mortality. OBJECTIVE: To describe trends in composition of uroliths in cats and evaluate risk factors related to age, breed, sex, urolith location, and bacterial urolith cultures. SAMPLE POPULATION: A total of 3940 uroliths and the cats from which they were obtained. METHODS: The database of the UC Davis Gerald V. Ling Urinary Stone Analysis Laboratory was searched for all urolith submissions from cats between January 2005 and December 2018. Mineral type, age, breed, sex, and urolith location and culture results were recorded. Trends were evaluated and variables compared to evaluate risk factors. RESULTS: A significant decrease in the proportion of calcium oxalate (CaOx)-containing uroliths occurred over time (P = .02), from 50.1% (204/407) of all submissions in 2005 to 37.7% (58/154) in 2018. In contrast, the proportion of struvite-containing uroliths increased significantly (P = .002), from 41.8% (170/407) in 2005 to 54.5% (84/154) in 2018. The proportion of CaOx-containing uroliths in the upper urinary tract was significantly higher compared to the proportion of other urolith types in the upper urinary tract. Urate-containing uroliths were the third most common type (361/3940, 9.2%). Overall, sex and age predispositions were similar to those reported previously. CONCLUSIONS AND CLINICAL IMPORTANCE: The decrease in the proportion of CaOx-containing uroliths and increase in the proportion of struvite-containing uroliths warrants investigation. Further education regarding the efficacy of medical dissolution of struvite-containing uroliths is recommended.

Retrospective Evaluation of Acute Kidney Injury After Zoledronic Acid Administration to Dogs With Malignant Osteolysis.

Zoledronic acid (ZOL) is an intravenous bisphosphonate indicated for the use of hypercalcemia of malignancy and management of bony metastases. Its therapeutic effect lies in the targeting of malignant osteoclasts; however, administration can be associated with renal toxicity. The objective of this retrospective study was to evaluate the frequency and severity of acute kidney injury (AKI) following ZOL administration in a cohort of cancer-bearing dogs. A pharmacy search was conducted to identify dogs that received a dose of ZOL between June 2016 and July 2019. Inclusion criteria included baseline and post-treatment chemistry panels. Medical records were reviewed to obtain clinical data including signalment, dose, dosage, number of treatments administered, and changes in renal function. Forty-four dogs met the inclusion criteria. Median number of doses administered was three [interquartile range (IQR), 2-5]. The median highest creatinine value occurred after a median of one dose (IQR, 1-2 doses) compared with the median highest value of blood urea nitrogen, phosphorus, and potassium, which occurred after a median of two doses (IQR, 1-3). Six (13.6%) dogs developed an AKI, and one dog (2.3%) had progression of an existing azotemia after treatment with ZOL was initiated. Two dogs (4.5%) had ZOL treatment discontinued secondary to development of azotemia. Use of concurrent administration of non-steroidal anti-inflammatory drugs or anesthesia did not significantly increase the risk of AKI in this cohort of dogs. Acute kidney injury is observed infrequently in cancer-bearing dogs treated with ZOL and is generally mild to moderate in severity; discontinuation of ZOL due to AKI is uncommon.

Suspected contrast-induced nephropathy in three sequential patients undergoing computed tomography angiography and transarterial embolization for nonresectable neoplasia.

CASE DESCRIPTION: During the same week, 3 sequential patients (a 10-year-old 8.7-kg spayed female poodle cross [dog 1], 13-year-old 2.6-kg spayed female domestic longhair cat, and 13-year-old 9.0-kg castrated male mixed-breed dog [dog 2]) underwent CT-angiography (day 0) and transarterial embolization (day 1) for nonresectable hepatocellular carcinoma (n = 2) or prostatic carcinoma (1). CLINICAL FINDINGS: Contrast-induced nephropathy (CIN) was suspected in all animals on the basis of higher serum creatinine concentrations after contrast medium administration (exposure), compared with baseline concentrations before exposure, consistent with CIN definitions. The total dose of contrast medium was < 3 mL/kg for each exposure. For all 3 patients, creatinine concentration peaked at a median of 3 days (range, 2 to 3 days) after the first exposure (day 0), and the median absolute and relative increases in creatinine concentration after exposure (vs baseline concentrations before exposure) were 2.9 mg/dL (range, 2.2 to 3.7 mg/dL) and 410% (range, 260 to 720%), respectively. TREATMENT AND OUTCOME: The patients received individually tailored supportive care for acute kidney injury. Serum creatinine concentrations began to improve at a median of 4 days (range, 3 to 4 days) and returned to within reference limits at a median of 7 days (range, 3 to 13 days) following initial exposure. CLINICAL RELEVANCE: CIN should be considered as a potential complication following IV administration of contrast medium. Short-term outcome following CIN can be excellent with supportive care.

Removal and repositioning of urinary tract implants by use of an endovascular snare system in dogs and cats (2013-2019).

OBJECTIVE: To report the fluoroscopic removal or repositioning of urinary tract implants in dogs and cats by use of an endovascular snare system (ESS) and to report procedural usefulness and complications in dogs and cats. ANIMALS: 3 cats and 14 dogs. PROCEDURES: A medical records review was performed to identify dogs and cats that underwent removal or repositioning of urinary tract foreign bodies or implants by use of an ESS with fluoroscopic guidance at a veterinary teaching hospital from 2013 to 2019. RESULTS: Dogs had a median weight of 25 kg (55 lb) with a range of 3.5 to 60.6 kg (7.7 to 133.3 lb), and cats had a median weight of 5 kg (11 lb) with a range of 4.2 to 5.4 kg (9.2 to 11.9 lb). By use of an ESS, 12 patients (2 cats and 10 dogs) underwent transurethral retrieval of retained vesicourethral implants or ureteral stents, 2 dogs underwent transurethral ureteral stent repositioning, 1 cat and 2 dogs underwent transnephric retrieval of ureteral stents, and 1 dog underwent cystoscopic-assisted transureteral ureteral stent retrieval. All procedures were successfully performed, and there were no associated procedural complications. CONCLUSIONS AND CLINICAL RELEVANCE: Retained vesicourethral implants or ureteral stents were successfully retrieved by use of an ESS in dogs and cats transurethrally or with an open or percutaneous transnephric approach and fluoroscopic guidance. These techniques should be considered as an alternative or adjunct to more invasive methods for implant retrieval or manipulation.